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Sample records for apneic oxygenation combined

  1. Apneic oxygenation combined with extracorporeal arteriovenous carbon dioxide removal provides sufficient gas exchange in experimental lung injury

    DEFF Research Database (Denmark)

    Nielsen, Niels Dalsgaard; Kjærgaard, Benedict; Nielsen, Jakob Koefoed;

    . The O2 uptake via the lungs was 185 (164-212) mL/min, whereas the O2 uptake via the Novalung was 4 (0-11) mL/min. PaCO2 increased exponentially towards a maximum value just below 8 kPa. The CO2 removal via the Novalung was 178 (148-178) mL/min and pH was 7.35 (7.33-7.37) during the experiment. CO was 8......Background and aim of study We hypothesized that continuous high airway pressure without ventilatory movements (apneic oxygenation), using an open lung approach, combined with extracorporeal, pumpless, arterio-venous, carbon dioxide (CO2) removal would provide adequate gas exchange in acute lung...... injury. The aim of this study was to test this hypothesis in a lung injury model using pigs of human adult size, to mimic the O2 consumption and the CO2 production of adult patients.   Materials and methods In eight anesthetized, tracheally intubated and mechanically ventilated pigs (85-95 kg), lung...

  2. Intraoperative Extracorporeal Carbon Dioxide Removal During Apneic Oxygenation with an EZ-Blocker in Tracheal Surgery.

    Science.gov (United States)

    Rispoli, Marco; Nespoli, Moana Rossella; Mattiacci, Dario Maria; Esposito, Marianna; Corcione, Antonio; Buono, Salvatore

    2016-06-01

    Tracheal surgery requires continued innovation to manage the anesthetic during an open airway phase. A common approach is apneic oxygenation with continuous oxygen flow, but the lack of effective ventilation causes hypercapnia, with respiratory acidosis. We used extracorporeal carbon dioxide removal for intraoperative decapneization during apneic oxygenation in a 64-year-old woman who was scheduled for tracheal surgery because of tracheal stenosis caused by long-term intubation. Our findings demonstrate that even after 40 minutes of total apnea, using an EZ-blocker for oxygenation and external decapneization, hemodynamic and gas exchange variables never demonstrated any dangerous alterations. PMID:27075426

  3. Alveolar accumulation/concentration of nitrogen during apneic oxygenation with arteriovenous carbon dioxide removal.

    Science.gov (United States)

    Nielsen, Niels D; Andersen, Gratien; Kjaergaard, Benedict; Staerkind, Mette E; Larsson, Anders

    2010-01-01

    In a model of acute lung injury (ALI), previously, we have shown that apneic oxygenation, using an inspiratory O2 fraction (FiO2) of 1.0 combined with extracorporeal arteriovenous CO2 removal (AO-AVCR) maintains adequate arterial O2 and CO2 levels for a prolonged period. However, it is important that FiO2 lower than 1.0 can be used to avoid possible pulmonary oxygen toxicity. In preliminary studies, arterial oxygenation decreased to extreme low levels, when FiO2 alveolar accumulation/concentration of N2 or by absorption atelectasis. In four anesthetized and mechanically ventilated pigs, mild lung injury was induced. After a lung recruitment maneuver, we initiated two 20-minute periods of AO-AVCR with FiO2 of 1 and 0.5, respectively. By using FiO2 = 1, PaO2 remained above 300 mm Hg. At the end of the period, the alveolar O2 fraction (FAO2) was 0.89 (0.88-0.89; median and ranges). With FiO2 = 0.5, PaO2 decreased 90% compared with baseline values and FAO2 decreased to 0.07 (0.06-0.07). No atelectasis was visible on computed tomography after either period, and we, therefore, conclude that the alveolar hypoxia was caused by the alveolar N2 accumulation/concentration and subsequently by the O2 depletion. PMID:20038832

  4. Prevention of hyaline membrane disease in premature lambs by apneic oxygenation and extracorporeal carbon dioxide removal.

    Science.gov (United States)

    Pesenti, A; Kolobow, T; Buckhold, D K; Pierce, J E; Huang, H; Chen, V

    1982-01-01

    Hyaline membrane disease is found only in lungs where pulmonary ventilation has been established, i.e. after birth. We delivered eleven fetal lambs of a gestational age of 128-130 days but instead kept their lungs in total apnea and inflated to constant pressure, while removing all metabolically produced carbon dioxide with an extracorporeal membrane lung. Oxygen was provided by the membrane lung, and by apneic oxygenation through the natural lungs. Hence, arterial blood gases remained always normal, without any pulmonary ventilation. After 6-66 h the lungs had sufficiently cleared to allow normal mechanical pulmonary ventilation in 10 our of 11 lambs so treated. In a control group treated with mechanical ventilation alone, five of seven lambs died within the first 24 h of severe hyaline membrane disease. PMID:6799556

  5. EEG Suppression Associated with Apneic Episodes in a Neonate

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    Evonne Low

    2012-01-01

    Full Text Available We describe the EEG findings from an ex-preterm neonate at term equivalent age who presented with intermittent but prolonged apneic episodes which were presumed to be seizures. A total of 8 apneic episodes were captured (duration 23–376 seconds during EEG monitoring. The baseline EEG activity was appropriate for corrected gestational age and no electrographic seizure activity was recorded. The average baseline heart rate was 168 beats per minute (bpm and the baseline oxygen saturation level was in the mid-nineties. Periods of complete EEG suppression lasting 68 and 179 seconds, respectively, were recorded during 2 of these 8 apneic episodes. Both episodes were accompanied by bradycardia less than 70 bpm and oxygen saturation levels of less than 20%. Short but severe episodes of apnea can cause complete EEG suppression in the neonate.

  6. Sensitization by pulmonary reactive oxygen species of rat vagal lung C-fibers: the roles of the TRPV1, TRPA1, and P2X receptors.

    Directory of Open Access Journals (Sweden)

    Ting Ruan

    Full Text Available Sensitization of vagal lung C-fibers (VLCFs induced by mediators contributes to the pathogenesis of airway hypersensitivity, which is characterized by exaggerated sensory and reflex responses to stimulants. Reactive oxygen species (ROS are mediators produced during airway inflammation. However, the role of ROS in VLCF-mediated airway hypersensitivity has remained elusive. Here, we report that inhalation of aerosolized 0.05% H2O2 for 90 s potentiated apneic responses to intravenous capsaicin (a TRPV1 receptor agonist, α,β-methylene-ATP (a P2X receptor agonist, and phenylbiguanide (a 5-HT3 receptor agonist in anesthetized rats. The apneic responses to these three stimulants were abolished by vagatomy or by perivagal capsaicin treatment, a procedure that blocks the neural conduction of VLCFs. The potentiating effect of H2O2 on the apneic responses to these VLCF stimulants was prevented by catalase (an enzyme that degrades H2O2 and by dimethylthiourea (a hydroxyl radical scavenger. The potentiating effect of H2O2 on the apneic responses to capsaicin was attenuated by HC-030031 (a TRPA1 receptor antagonist and by iso-pyridoxalphosphate-6-azophenyl-2',5'-disulphonate (a P2X receptor antagonist. The potentiating effect of H2O2 on the apneic responses to α,β-methylene-ATP was reduced by capsazepine (a TRPV1 receptor antagonist, and by HC-030031. The potentiating effect of H2O2 on the apneic responses to phenylbiguanide was totally abolished when all three antagonists were combined. Consistently, our electrophysiological studies revealed that airway delivery of aerosolized 0.05% H2O2 for 90 s potentiated the VLCF responses to intravenous capsaicin, α,β-methylene-ATP, and phenylbiguanide. The potentiating effect of H2O2 on the VLCF responses to phenylbiguanide was totally prevented when all antagonists were combined. Inhalation of 0.05% H2O2 indeed increased the level of ROS in the lungs. These results suggest that 1 increased lung ROS sensitizes

  7. Size matters: Spleen and lung volumes predict performance in human apneic diving

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    Erika eSchagatay

    2012-06-01

    Full Text Available Humans share with e.g. seals the ability to contract the spleen and increase circulating hematocrit, which may improve apneic performance by enhancing gas storage. Seals have large spleens and while human spleen size is small in comparison, it shows great individual variation. Unlike many marine mammals, human divers rely to a great extent on lung oxygen stores, but the impact of lung volume on competitive apnea performance has never been determined. We studied if spleen- and lung size correlated with performance in elite apnea divers. Volunteers were 14 male apnea world championship participants, with a mean(SE of 5.8(1.2 years of previous apnea training. Spleen volume was calculated from spleen length, width and thickness measured via ultrasound during rest, and vital capacity via spirometry. Accumulated competition scores from dives of maximal depth, time and distance were compared to anthropometric measurements and training data. Mean dive performance was 75(4 m for constant weight depth, 5 min 53(39 s for static apnea and 139(13 m for dynamic apnea distance. Subjects’ mean height was 184(2 cm, weight 82(3 kg, vital capacity (VC 7.3(0.3 L and spleen volume 336(32 ml. Spleen volume did not correlate with subject height or weight, but was positively correlated with competition score (r=0.57; P<0.05. Total competition score was also positively correlated with VC (r=0.54; P<0.05. The three highest scoring divers had the greatest spleen volumes, averaging 538(53 ml, while the three lowest scoring divers had a volume of 270(71 ml (P<0.01. VC was also greater in the high-scorers, at 7.9(0.36 L as compared to 6.7(0.19 L in the low-scorers (P<0.01. Spleen volume was reduced to half after 2 min of apnea in the highest scoring divers, and the estimated resting apnea time gain from the difference between high and low scorers was 15 s for spleen volume and 60 s for VC. We conclude that both spleen- and lung volume predict apnea performance in elite

  8. Prevalence of Gastroesophageal Reflux in Infants with Recurrent Brief Apneic Episodes

    OpenAIRE

    Sheikh, Shahid; Thomas C Stephen; Sisson, Barbara

    1999-01-01

    BACKGROUND: Apnea in an infant can be a diagnostic dilemma for the treating pediatrician. It is suggested that in some infants, gastroesophageal reflux (GER) might be a factor in the pathogenesis of apnea, although its role as a cause of apnea is still controversial.OBJECTIVE: To evaluate the prevalence of GER in infants presenting with recurrent brief apneic periods.PATIENTS AND METHODS: A retrospective review of the medical records of all the infants who underwent prolonged esophageal pH st...

  9. Compensatory responses to upper airway obstruction in obese apneic men and women

    OpenAIRE

    Chin, Chien-Hung; Kirkness, Jason P.; Patil, Susheel P.; McGinley, Brian M.; Smith, Philip L.; Schwartz, Alan R.; Schneider, Hartmut

    2011-01-01

    Defective structural and neural upper airway properties both play a pivotal role in the pathogenesis of obstructive sleep apnea. A more favorable structural upper airway property [pharyngeal critical pressure under hypotonic conditions (passive Pcrit)] has been documented for women. However, the role of sex-related modulation in compensatory responses to upper airway obstruction (UAO), independent of the passive Pcrit, remains unclear. Obese apneic men and women underwent a standard polysomno...

  10. Balloon Dilatation of Pediatric Subglottic Laryngeal Stenosis during the Artificial Apneic Pause: Experience in 5 Children

    Directory of Open Access Journals (Sweden)

    J. Lisý

    2014-01-01

    Full Text Available Introduction. Balloon dilatation is a method of choice for treatment of laryngeal stenosis in children. The aim of procedure in apneic pause is to avoid new insertion of tracheostomy cannula. Patients and Methods. The authors performed balloon dilatation of subglottic laryngeal strictures (SGS in 5 children (3 girls and 2 boys without tracheotomy. Two of them with traumatic and inflammatory SGS had a tracheal cannula removed in the past. The other 3 children with postintubation SGS had never had a tracheostomy before. The need for tracheostomy due to worsening stridor was imminent for all of them. Results. The total of seven laryngeal dilatations by balloon esophagoplasty catheter in apneic pause was performed in the 5 children. The procedure averted the need for tracheostomy placement in 4 of them (80%. Failure of dilatation in girl with traumatic stenosis and concomitant severe obstructive lung disease led to repeated tracheostomy. Conclusion. Balloon dilatation of laryngeal stricture could be done in the absence of tracheostomy in apneic pause. Dilatation averted threatening tracheostomy in all except one case. Early complication after the procedure seems to be a negative prognostic factor for the outcome of balloon dilatation.

  11. Plethysmographic estimation of thoracic gas volume in apneic mice.

    Science.gov (United States)

    Jánosi, Tibor Z; Adamicza, Agnes; Zosky, Graeme R; Asztalos, Tibor; Sly, Peter D; Hantos, Zoltán

    2006-08-01

    Electrical stimulation of intercostal muscles was employed to measure thoracic gas volume (TGV) during airway occlusion in the absence of respiratory effort at different levels of lung inflation. In 15 tracheostomized and mechanically ventilated CBA/Ca mice, the value of TGV obtained from the spontaneous breathing effort available in the early phase of the experiments (TGVsp) was compared with those resulting from muscle stimulation (TGVst) at transrespiratory pressures of 0, 10, and 20 cmH2O. A very strong correlation (r2= 0.97) was found, although with a systematically (approximately 16%) higher estimation of TGVst relative to TGVsp, attributable to the different durations of the stimulated (approximately 50 ms) and spontaneous (approximately 200 ms) contractions. Measurements of TGVst before and after injections of 0.2, 0.4, and 0.6 ml of nitrogen into the lungs in six mice resulted in good agreement between the change in TGVst and the injected volume (r2= 0.98). In four mice, TGVsp and TGVst were compared at end expiration with air or a helium-oxygen mixture to confirm the validity of isothermal compression in the alveolar gas. The TGVst values measured at zero transrespiratory pressure in all CBA/Ca mice [0.29 +/- 0.05 (SD) ml] and in C57BL/6 (N = 6; 0.34 +/- 0.08 ml) and BALB/c (N = 6; 0.28 +/- 0.06 ml) mice were in agreement with functional residual capacity values from previous studies in which different techniques were used. This method is particularly useful when TGV is to be determined in the absence of breathing activity, when it must be known at any level of lung inflation or under non-steady-state conditions, such as during pharmaceutical interventions. PMID:16645196

  12. Combined oxides as oxygen-carrier material for chemical-looping with oxygen uncoupling

    International Nuclear Information System (INIS)

    Highlights: • Manganese-based combined oxides are examined for chemical-looping combustion applications. • Promising compositions includes (MnyFe1−y)Ox, (MnySi1−y)Ox and CaMnO3−δ. • Study includes thermodynamic analysis and overview of current experimental experiences. - Abstract: Oxygen-carrier materials for chemical-looping with oxygen uncoupling (CLOU) must be capable of taking up and releasing gas-phase O2 at conditions relevant for generation of heat and power. In principle, the capability of a certain material to do so is determined by its thermodynamic properties. This paper provides an overview of the possibility to design feasible oxygen carrier materials from combined oxides, i.e. oxides with crystal structures that include several different cations. Relevant literature is reviewed and the thermodynamic properties and key characteristics of a few selected combined oxide systems are calculated and compared to experimental data. The general challenges and opportunities of the combined oxide concept are discussed. The focus is on materials with manganese as one of its components and the following families of compounds and solid solutions have been considered: (MnyFe1−y)Ox, (MnySi1−y)Ox, CaMnO3−δ, (NiyMn1−y)Ox, (MnyCu1−y)Ox and (MnyMg1−y)Ox. In addition to showing promise from a thermodynamic point of view, reactivity data from experimental investigations suggests that the rate of O2 release can be high for all systems. Thus these combined oxides could also be very suitable for practical application

  13. Christine Angot or the Autofiction as Apneic Literature

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    Alexandru MATEI

    2013-01-01

    Full Text Available A new literary genre is theorised in the seventies in France, autofiction, which combines characteristics of autobiography (especially what is called the nominal pact, the fact the the first person narrative has the same name as the author’s and of fiction (especially what is called symbolic conversion, in that the facts are not entirely realistic. There are in fact two kinds of autofiction : one which emphasizes on fiction (for instance a novel called Truismes by Marie Darrieussecq and the other one whose interest resides on encoding the “author’s” voice. The last kind of autofiction, illustrated here by Christine Angot’s books published from early 90’s, has not been clearly defined by narratologists, because its definition requires a deeper commitment of scholars in social description that formalist literary studies are not able to give. The signification of this literature is not to be established by a post-romantic aesthetics, and one proof would be Christine Angot’s novel Inceste: a “her-story” told in direct speech, to which the reader listen more than he reads it. What is transmitted is more an emergency of talking underlining a forgotten force of literature: the “immediate” expression of a psyche, of a human energy. Is that literature or not? Is it “for real” or only a literary convention made to impress the reader and to suspend all “aesthetic judgment”?

  14. Heart rate variability in non-apneic snorers and controls before and after continuous positive airway pressure

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    Mateika Jason H

    2005-07-01

    Full Text Available Abstract Background We hypothesized that sympathetic nervous system activity (SNSA is increased and parasympathetic nervous system activity (PNSA is decreased during non-rapid eye movement (NREM sleep in non-apneic, otherwise healthy, snoring individuals compared to control. Moreover, we hypothesized that these alterations in snoring individuals would be more evident during non-snoring than snoring when compared to control. Methods To test these hypotheses, heart rate variability was used to measure PNSA and SNSA in 11 normotensive non-apneic snorers and 12 control subjects before and 7-days after adapting to nasal continuous positive airway pressure (nCPAP. Results Our results showed that SNSA was increased and PNSA was decreased in non-apneic snorers during NREM compared to control. However, these changes were only evident during the study in which snoring was eliminated with nCPAP. Conversely, during periods of snoring SNSA and PNSA were similar to measures obtained from the control group. Additionally, within the control group, SNSA and PNSA did not vary before and after nCPAP application. Conclusion Our findings suggest that long-lasting alterations in autonomic function may exist in snoring subjects that are otherwise healthy. Moreover, we speculate that because of competing inputs (i.e. inhibitory versus excitatory inputs to the autonomic nervous system during snoring, the full impact of snoring on autonomic function is most evident during non-snoring periods.

  15. Combined application of XANES and XPS to study oxygen species adsorbed on Ag foil

    CERN Document Server

    Bukhtiyarov, V I; Kaichev, V V; Knop-Gericke, A; Mayer, R W; Schloegl, R

    2001-01-01

    Adsorbed oxygen species realized in the course of ethylene epoxidation over polycrystalline silver have been characterized by X-ray absorption near the edge structure and X-ray photoelectron spectroscopy. Namely, the combined application of XANES and XPS in similar UHV conditions using the same sample allowed us to assign an XAS feature to the nucleophilic and electrophilic oxygen. This is of great significance, since these species are suggested to be included into the active center for ethylene epoxidation. The differences in the oxygen-silver bonding of these oxygen species are discussed.

  16. Hyperbaric oxygen therapy combined with Schwann cell transplantation promotes spinal cord injury recover y

    Institute of Scientific and Technical Information of China (English)

    Chuan-gang Peng; Shu-quan Zhang; Min-fei Wu; Yang Lv; Dan-kai Wu; Qi Yang; Rui Gu

    2015-01-01

    Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantationviathe tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These ifndings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury.

  17. Hyperbaric oxygen therapy combined with Schwann cell transplantation promotes spinal cord injury recovery

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    Chuan-gang Peng

    2015-01-01

    Full Text Available Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantation via the tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These findings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury.

  18. Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

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    Paulo Cesar Fagundes Neves

    2013-09-01

    Full Text Available OBJECTIVES: The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures. METHODS: A total of 128 male New Zealand albino rabbits, between 6-8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each: control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red. RESULTS: Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group. CONCLUSION: Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model.

  19. ACUPUNCTURE COMBINED WITH INHALATION OF OXYGEN FOR TREATMENT OF 60 CASES OF EXTENSIVE ANXIETY

    Institute of Scientific and Technical Information of China (English)

    DU Hong

    2005-01-01

    Objective: To observe the therapeutic effects and adverse effects of "channel-oxygen therapy" for extensive anxiety. Methods: Sixty cases of extensive anxiety patients were treated with "channel-oxygen therapy" once daily and continuously for 4 weeks. Neiguan(内关PC 6) and Zusanli(足三里ST 36) were needled in combination with nasal inhalation of oxygen, 30 min each session. The therapeutic effects were assessed by Hamilton Anxiety Scale (HAMA) and the adverse effects by Treatment Emergent Symptom Scale (TESS). Results: Of the 60 cases, 35 were cured, 13 improved and 12 were ineffective, with the effective rate being 80.0% and the cured rate 58.3%. No evident adverse effects were found. Conclusion: The "channel-oxygen therapy" is safe and effective for extensive anxiety.

  20. Detailing renal hemodynamics and oxygenation in rats by a combined near-infrared spectroscopy and invasive probe approach.

    Science.gov (United States)

    Grosenick, Dirk; Cantow, Kathleen; Arakelyan, Karen; Wabnitz, Heidrun; Flemming, Bert; Skalweit, Angela; Ladwig, Mechthild; Macdonald, Rainer; Niendorf, Thoralf; Seeliger, Erdmann

    2015-02-01

    We hypothesize that combining quantitative near-infrared spectroscopy (NIRS) with established invasive techniques will enable advanced insights into renal hemodynamics and oxygenation in small animal models. We developed a NIRS technique to monitor absolute values of oxygenated and deoxygenated hemoglobin and of oxygen saturation of hemoglobin within the renal cortex of rats. This NIRS technique was combined with invasive methods to simultaneously record renal tissue oxygen tension and perfusion. The results of test procedures including occlusions of the aorta or the renal vein, hyperoxia, hypoxia, and hypercapnia demonstrated that the combined approach, by providing different but complementary information, enables a more comprehensive characterization of renal hemodynamics and oxygenation. PMID:25780726

  1. Detailing renal hemodynamics and oxygenation in rats by a combined near-infrared spectroscopy and invasive probe approach

    Science.gov (United States)

    Grosenick, Dirk; Cantow, Kathleen; Arakelyan, Karen; Wabnitz, Heidrun; Flemming, Bert; Skalweit, Angela; Ladwig, Mechthild; Macdonald, Rainer; Niendorf, Thoralf; Seeliger, Erdmann

    2015-01-01

    We hypothesize that combining quantitative near-infrared spectroscopy (NIRS) with established invasive techniques will enable advanced insights into renal hemodynamics and oxygenation in small animal models. We developed a NIRS technique to monitor absolute values of oxygenated and deoxygenated hemoglobin and of oxygen saturation of hemoglobin within the renal cortex of rats. This NIRS technique was combined with invasive methods to simultaneously record renal tissue oxygen tension and perfusion. The results of test procedures including occlusions of the aorta or the renal vein, hyperoxia, hypoxia, and hypercapnia demonstrated that the combined approach, by providing different but complementary information, enables a more comprehensive characterization of renal hemodynamics and oxygenation. PMID:25780726

  2. Combined Water-Oxygen Pinch Analysis with Mathematical Programming for Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    宋丽丽; 都健; 柴绍斌; 姚平经

    2006-01-01

    Water-oxygen pinch analysis is an effective method to decrease the wastewater quantity and improve the wastewater quality. But when multiple-contaminants are present, the method is difficult to be carried out. In this paper, the method that combines water-oxygen pinch analysis with mathematical programming is proposed. It obtains the general optimal solution and leads to the reuse stream that cannot be found only by pinch analysis. The new method is illustrated by an example, and the annual cost is reduced by 8.43% compared with the solution of literature.

  3. Combined impact of water column oxygen and temperature on internal oxygen status and growth of Zostera marina seedlings and adult shoots

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens

    2013-01-01

    Eelgrass (Zostera marina L.) occasionally experiences severe die-offs during warm summer periods with variable water column oxygen partial pressures (pO). Eelgrass is known to be very intolerant to tissue anoxia with reduced growth and increasing mortality after ≤12h anoxia in the dark at...... temperatures of ≥25°C. In the present study we experimentally examine the impact of combined water column oxygen and temperature on oxygen dynamics in leaf meristems of seedlings and adult shoots to better understand how stressful environmental conditions affect eelgrass oxygen dynamics and subsequent growth...... and mortality. There was a strong interaction between water column oxygen and temperature on meristem pO implying that eelgrass is rather resistant to unfavorable oxygen conditions in winter but becomes increasingly vulnerable in summer, especially at high temperatures. At 25°C meristems became anoxic...

  4. Hyperbaric oxygen combined with drug therapy in the treatment of acute cerebral infarction clinical analysis

    Institute of Scientific and Technical Information of China (English)

    Wen-Cui Lin; Kang Lin; Jing Wang; Shuai Li

    2015-01-01

    Objective:To explore the effects of hyperbaric oxygen combined with edaravone, salviae miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction clinical analysis.Methods: A total of 200 cases of acute cerebral infraction patients were randomly divided into observation group and control group. The control group was treated with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel; on the basis of treatment in control group, the observation group was combined with hyperbaric oxygen therapy. The neurological deficit scores were observed before and after treatment in patients of two groups, meanwhile the activities of daily living (ADL) and clinical effects were compared.Results: The total effective rate in observation group (92%) was significantly higher than control group (79%), the differences were statistically significant; the score of ADL in observation group after treatment was obviously higher than control group [(79.91±5.16)vs (61.62±5.60)], and the differences were statistically significant. The neurological deficit scores after treatment were obviously lower than the control group [(9.55±4.13)vs (15.46±4.92)], the differences were statistically significant.Conclusion: Hyperbaric oxygen combined with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction can improve the symptoms of microcirculation and neurologic impairment, and improve the patient s quality of life.

  5. Effects of combined radiofrequency radiation exposure on levels of reactive oxygen species in neuronal cells

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the effects of the combined RF radiation (837 MHz CDMA plus 1950 MHz WCDMA) signal on levels of intracellular reactive oxygen species (ROS) in neuronal cells. Exposure of the combined RF signal was conducted at specific absorption rate values of 2 W/kg of CDMA plus 2 W/kg of WCDMA for 2 h. Co-exposure to combined RF radiation with either H2O2 or menadione was also performed. The experimental exposure groups were incubator control, sham-exposed, combined RF radiation-exposed with or without either H2O2 or menadione groups. The intracellular ROS level was measured by flow cytometry using the fluorescent probe dichlorofluorescein diacetate. Intracellular ROS levels were not consistently affected by combined RF radiation exposure alone in a time-dependent manner in U87, PC12 or SH-SY5Y cells. In neuronal cells exposed to combined RF radiation with either H2O2 or menadione, intracellular ROS levels showed no statically significant alteration compared with exposure to menadione or H2O2 alone. These findings indicate that neither combined RF radiation alone nor combined RF radiation with menadione or H2O2 influences the intracellular ROS level in neuronal cells such as U87, PC12 or SH-SY5Y. (author)

  6. Toxicity prediction of binary combinations of cadmium, carbendazim and low dissolved oxygen on Daphnia magna

    International Nuclear Information System (INIS)

    Environmental contamination is often characterised by a combination of stress factors of various sources (biological, physical and chemical). The predictability of their joint effects is an important stage in environmental risk assessment procedures. In this study, the two main conceptual models for mixture evaluation based on the effect of individual compounds, concentration addition (CA) and independent action (IA) and deviations to synergism/antagonism, 'dose ratio' and 'dose level' dependency were used. The single and combined effects of cadmium, carbendazim and low dissolved oxygen levels were assayed for life-cycle parameters (survival and feeding) of the water flea Daphnia magna Straus. The results of single exposures revealed an increase of acute and chronic toxicity as concentrations of cadmium and carbendazim increases. At low dissolved oxygen levels both survival and feeding parameters were significantly affected (P ≤ 0.05). In the acute mixture exposure of cadmium and carbendazim a 'dose ratio' dependency was observed with a higher toxicity when cadmium was dominant whereas at high concentrations of carbendazim a lower effect on survival was observed. At chronic exposures an antagonistic deviation from IA model was observed for this mixture. The IA model showed to be adequate for toxicity prediction on acute exposure combinations with low DO levels where a synergistic behaviour was observed. However, at sublethal exposures IA and CA models failed by underestimation. Validation from toxicokinetic and toxicodynamic modelling studies should be made in the future as a way to understand toxicological pathways involved in complex mixture/combination exposures

  7. A hydrogen and oxygen combined cycle with chemical-looping combustion

    International Nuclear Information System (INIS)

    Highlights: • A new system integrating CLC and the H2 and O2 combined cycle was proposed. • The new system has been investigated with the aid of the exergy principle. • The net efficiency of new system is 59.8% with CO2 capture when TIT is 1300 °C. • Efficiency are 8–12% higher than combined cycle with CO2 capture. - Abstract: In the current paper, new systems integrating chemical-looping hydrogen (CLH) generation and the hydrogen (H2) and oxygen (O2) combined cycle have been proposed. The new methane-fueled cycle using CLH has been investigated with the aid of the exergy principle (energy utilization diagram methodology). First, H2 is produced in the CLH, in which FeO and Fe3O4 are used as the looping material. The H2 and O2 combined cycle then uses H2 as fuel. Two types of these combined cycles have been analyzed. Waste heat from the H2–O2 combined cycle is utilized in the CLH to produce H2. The advantages of CLH and the H2 and O2 combined cycle have resulted in a breakthrough in performance. The new system can achieve 59.8% net efficiency with CO2 separation when the turbine inlet temperature is 1300 °C. Meanwhile, the cycle is environmentally superior because of the recovery of CO2 without an energy penalty

  8. Spatial Resolution of Combined Wavelength Modulation Spectroscopy with Integrated Cavity Output Spectroscopy for Atomic Oxygen Detection

    Science.gov (United States)

    Matsui, Makoto; Nakajima, Daisuke

    2015-09-01

    For developments of thermal protection system, atomic oxygen plays important role. However, its measurement method has not been established because the pressure in front of TPS test materials is as high as a few kPa. Our group proposed combined wavelength modulation and integrated output spectroscopies based on the forbidden transition at OI 636 nm to measure the ground-state number densities. In this study, WM-ICOS system is developed and applied to a microwave oxygen plasma to evaluate measurable region. As a result, the estimated number density by ICOS could be measured as low as 1021 m21. For the condition, WM-ICOS was applied. The signal to noise ratio of the 2f signal was 40.4. Then, the sensitivity was improved about 26. This result corresponding to the measurement limit of the partial atomic oxygen pressure of 250 Pa. The sensitivity of WM-ICOS was found to enough to diagnose the shock layer in high enthalpy flows. However, the spatial resolution was as large as 8 mm. The size of the beam pattern depends on the cavity length, robust ness of the cavity and accuracy of the cavity alignment. In this presentation, the relationship among these parameters will be discussed.

  9. Toxicity prediction of binary combinations of cadmium, carbendazim and low dissolved oxygen on Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Abel L.G. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)], E-mail: abel@ua.pt; Loureiro, Susana; Soares, Amadeu M.V.M. [Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro (Portugal)

    2008-08-11

    Environmental contamination is often characterised by a combination of stress factors of various sources (biological, physical and chemical). The predictability of their joint effects is an important stage in environmental risk assessment procedures. In this study, the two main conceptual models for mixture evaluation based on the effect of individual compounds, concentration addition (CA) and independent action (IA) and deviations to synergism/antagonism, 'dose ratio' and 'dose level' dependency were used. The single and combined effects of cadmium, carbendazim and low dissolved oxygen levels were assayed for life-cycle parameters (survival and feeding) of the water flea Daphnia magna Straus. The results of single exposures revealed an increase of acute and chronic toxicity as concentrations of cadmium and carbendazim increases. At low dissolved oxygen levels both survival and feeding parameters were significantly affected (P {<=} 0.05). In the acute mixture exposure of cadmium and carbendazim a 'dose ratio' dependency was observed with a higher toxicity when cadmium was dominant whereas at high concentrations of carbendazim a lower effect on survival was observed. At chronic exposures an antagonistic deviation from IA model was observed for this mixture. The IA model showed to be adequate for toxicity prediction on acute exposure combinations with low DO levels where a synergistic behaviour was observed. However, at sublethal exposures IA and CA models failed by underestimation. Validation from toxicokinetic and toxicodynamic modelling studies should be made in the future as a way to understand toxicological pathways involved in complex mixture/combination exposures.

  10. Oxygen-blown gasification combined cycle: Carbon dioxide recovery, transport, and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.R.

    1996-12-31

    This project emphasizes CO2-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems, CO2 transportation, and options for the long-term sequestration Of CO2. The intent is to quantify the CO2 budget, or an ``equivalent CO2`` budget, associated with each of the individual energy-cycle steps, in addition to process design capital and operating costs. The base case is a 458-MW (gross generation) IGCC system that uses an oxygen-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, bituminous coal feed, and low-pressure glycol sulfur removal, followed by Claus/SCOT treatment, to produce a saleable product. Mining, feed preparation, and conversion result in a net electric power production for the entire energy cycle of 411 MW, with a CO2 release rate of 0.801 kg/kV-Whe. For comparison, in two cases, the gasifier output was taken through water-gas shift and then to low-pressure glycol H2S recovery, followed by either low-pressure glycol or membrane CO2 recovery and then by a combustion turbine being fed a high-hydrogen-content fuel. Two additional cases employed chilled methanol for H2S recovery and a fuel cell as the topping cycle, with no shift stages. From the IGCC plant, a 500-km pipeline takes the CO2 to geological sequestering. For the optimal CO2 recovery case, the net electric power production was reduced by 37.6 MW from the base case, with a CO2 release rate of 0.277 kg/kWhe (when makeup power was considered). In a comparison of air-blown and oxygen-blown CO2-release base cases, the cost of electricity for the air-blown IGCC was 56.86 mills/kWh, while the cost for oxygen-blown IGCC was 58.29 mills/kWh. For the optimal cases employing glycol CO2 recovery, there was no clear advantage; the cost for air-blown IGCC was 95.48 mills/kWh, and the cost for the oxygen-blown IGCC was slightly lower, at 94.55 mills/kWh.

  11. The use of combined hyperbaric oxygenation and erythropoietin in the treatment of cardiac insufficiency

    Directory of Open Access Journals (Sweden)

    Živković Miodrag

    2007-01-01

    Full Text Available Introduction The aim of this research is to EVALUATE therapy efficiacy of hyperbaric oxygenation (HBO with regenerative effects on human tissues and erythropoietin, as a nonspecific growth factor. Material and methods This study included a group of 9 patients with echocardiographically diagnosed cardiac insufficiency with ejection fraction (EF% under 60%. HBO was used according to the protocol for patients with severe cardiac insufficiency (a total of 15 treatments. All patients also received subcutaneous erythropoietin, 2000 iv, every other day. Control echocardiography was done 30-45 days after they finished their treatments. Results The average ejection fraction before treatment was 46%. After treatment, the average EF% was 57%, so it increased by 11%. All patients felt subjectively better, with improved capacity to physical efforts. Discussion and Conclusion Ejection fraction of 30-40% is an indication for hyperbaric oxygenation therapy. The decision about the treatment is made by the physician based on his experience, general condition of the patient, frequency and severity of hypoxic episodes. If EF% is 30% or below, HBO is not recommended, because antioxidative defense mechanisms are exhausted under hypoxia and the balance of the organism should not be changed. An increase in average EF% by 11% demonstrates that combined use of HBO and Erythropoietin gives good results.

  12. A combined photocatalytic determination system for chemical oxygen demand with a highly oxidative reagent

    International Nuclear Information System (INIS)

    This study focuses on the proposal and validation of a combined photocatalytic (PC) system and a three-parameterized procedure for the determination of chemical oxygen demand (COD; PcCODcombined), with a highly oxidative reagent utilized as a photoelectron scavenger and signal indicator. The PcCODcombined was the functional combination of photon-efficient thin-layer photocatalytic oxidation, conventional bulk-phase photocatalytic oxidation and photocarrier-efficient high-activity photocatalytic reduction in one single photodigestion system, and consequently, this system possessed high photon-utilization efficiency, automatic stirring function and satisfactory determination characteristics. In comparison with the conventional one-parameterized procedure, the three-parameterized procedure introduces the blank and total photocatalytic reduction responses as two of the three significant analytical parameters. Under the optimized pH value of 3.0-4.5 and a rotating rate of 40 rpm, the representative KMnO4 species was used for the PcCODcombined system as the combined high-activity oxidant, and a narrow and reliable analytical linear range of 0-260 mg L-1 was achieved during the 10 min duration of the determinations. No observable interference of Cl- was found at concentration of the ion up to 2000 mg L-1. A real sample analysis indicated that the measured values for the PcCODcombined were all within a relative deviation below 5% of CODCr of the standard method, which further validates the practical feasibility of the proposed PcCODcombined system.

  13. In vitro oxygen-dependent survival of two human cell lines after combined radiations tirapazamin and cisplatin

    International Nuclear Information System (INIS)

    Recent data have shown that the in vitro and in vivo cytotoxicity of bioreductive drugs could be significantly cytotoxicity of bioreductive drugs could be significantly increased by combination with ionising radiation or chemotherapy. Various parameters such as oxygen tension and timing of administration of the drugs could play a crucial role in the efficacy of combined treatment modalities. The aim of this study was to define the oxygen dependency of cell survival after in vitro irradiation and incubation with tirapazamin, a bioreductive drug, and cisplatin given alone or simultaneously. Two human cell lines were studied: one cell line sensitive to tirapazamin, Na11+, a pigmented melanoma with a high percentage of hypoxic cells, and a less sensitive cell line to tirapazamin, HRT18, a rectal adenocarcinoma. Gas changes were made to study cell survival at four different oxygen concentrations (pO2): air (20.9 % O2), 10.2 and 0.2 %. Cells were incubated with tirapazamin and cisplatin alone or combined for one hour at 37 deg C, then irradiated and cultured. For Na11+, cell survival after irradiation was comparable in air and at 10 % oxygen with the two drugs given alone or combined. At 2 and 0.2 % oxygen, cell killing was largely increased by tirapazamin and was not modified by the addition of cisplatin. For HRT18, cell survival was not modified when cisplatin was added to radiation, whatever the oxygen partial pressure. At low pO2 (2 and 0.2 %) the cytotoxic effect of tirapazamin was not significantly decreased by the addition of cisplatin. When cytotoxic and bioreductive drugs are combined to radiation, the magnitude of the observed effect is highly dependent on the partial oxygen pressure and on the sensitivity of the cell line to the individual drugs. This has very important implications for clinical strategies based on combined chemo-radiotherapy. (authors)

  14. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Science.gov (United States)

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  15. Estimation of Biological Oxygen Demand and Chemical Oxygen Demand for Combined Sewer Systems Using Synchronous Fluorescence Spectra

    Directory of Open Access Journals (Sweden)

    Dae-Hee Park

    2010-03-01

    Full Text Available Real-time monitoring of water quality for sewer system is required for efficient sewer network design because it provides information on the precise loading of pollutant to wastewater treatment facilities and the impact of loading on receiving water. In this study, synchronous fluorescence spectra and its first derivatives were investigated using a number of wastewater samples collected in sewer systems in urban and non-urban areas, and the optimum fluorescence feature was explored for the estimation of biochemical oxygen demand (BOD and chemical oxygen demand (COD concentrations of sewer samples. The temporal variations in BOD and COD showed a regular pattern for urban areas whereas they were relatively irregular for non-urban areas. Irrespective of the sewer pipes and the types of the areas, two distinct peaks were identified from the synchronous fluorescence spectra, which correspond to protein-like fluorescence (PLF and humic-like fluorescence (HLF, respectively. HLF in sewer samples appears to be associated with fluorescent whitening agents. Five fluorescence characteristics were selected from the synchronous spectra and the first-derivatives. Among the selected fluorescence indices, a peak in the PLF region (i.e., Index I showed the highest correlation coefficient with both BOD and COD. A multiple regression approach based on suspended solid (SS and Index I used to compensate for the contribution of SS to BOD and COD revealed an improvement in the estimation capability, showing good correlation coefficients of 0.92 and 0.94 for BOD and COD, respectively.

  16. Effect of the Combination of Ezetimibe and Simvastatin on Gluconeogenesis and Oxygen Consumption in the Rat Liver.

    Science.gov (United States)

    Bracht, Lívia; Caparroz-Assef, Silvana Martins; Bracht, Adelar; Bersani-Amado, Ciomar Aparecida

    2016-06-01

    The aim of this work was to investigate the effects of chronic treatment with the combination of ezetimibe and simvastatin on gluconeogenesis in rat liver. Rats were treated daily for 28 days with the combination of ezetimibe and simvastatin (10/40 mg/kg) by oral gavage. To measure gluconeogenesis and the associated pathways, isolated perfused rat liver was used. In addition, subcellular fractions, such as microsomes and mitochondria, were used for complementary measures of enzymatic activities. Treatment with the combination of simvastatin and ezetimibe resulted in a decrease in gluconeogenesis from pyruvate (-62%). Basal oxygen consumption of the treated animals was higher (+22%) than that of the control rats, but the resulting oxygen consumption that occurred after pyruvate infusion was 43% lower in animals treated with the combination of simvastatin and ezetimibe. Oxygen consumption in the livers from treated animals was completely inhibited by cyanide (electron transport chain inhibitor), but not by proadifen (cytochrome P450 inhibitor). Chronic treatment with ezetimibe/simvastatin decreased the activity of the key enzymes glucose-6-phosphatase and fructose-1,6-bisphosphatase by 59% and 45%, respectively, which is probably the major reason for the decreased gluconeogenesis seen in ezetimibe-/simvastatin-treated rats. It is also possible that part of the effect of this combination on gluconeogenesis and on the oxygen consumption is related to the impairment of mitochondrial energy transduction. PMID:26552039

  17. A fascinating combination of Co, Ni and Al nanomaterial for oxygen evolution reaction

    Science.gov (United States)

    Khan, Sher Bahadar; Khan, Shahid Ali; Asiri, Abdullah M.

    2016-05-01

    Interesting combination of Co, Ni and Al have been assessed for oxygen evolution reaction (OER). Layered double hydroxide (LDH) nanosheets of NiCoAl, Co-Al oxide nanoparticles and Co-Ni oxide nanoparticles were prepared and studied for the first time as OER catalyst. Among all the subjected catalysts, the binary LDH comprise of NiCoAl showed comparatively high catalytic activity than Co-Al oxide nanoparticles and Co-Ni oxide nanoparticles. The Co-Al and Co-Ni oxide nanoparticles showed current densities of 34.6 and 24.5 mA cm-2, respectively at 1 V in 0.3 M KOH solution. However at the same conditions, NiCoAl-LDH showed comparatively low overpotential, high current density (40.8 mA cm-2) and lower Tafel slope. The low overpotential and high catalytic activity of NiCoAl-LDH stipulate the possibility to reduce the demand of precious, rare earth and expensive transition metal catalyst in electrochemical water splitting for OER.

  18. Combining oxygen plasma treatment with anchorage of cationized gelatin for enhancing cell affinity of poly(lactide-co-glycolide).

    Science.gov (United States)

    Shen, Hong; Hu, Xixue; Yang, Fei; Bei, Jianzhong; Wang, Shenguo

    2007-10-01

    Surface characteristics greatly influence attachment and growth of cells on biomaterials. Although polylactone-type biodegradable polymers have been widely used as scaffold materials for tissue engineering, lack of cell recognition sites, poor hydrophilicity and low surface energy lead to a bad cell affinity of the polymers, which limit the usage of polymers as scaffolds in tissue engineering. In the present study, surface of poly (L-lactide-co-glycolide) (PLGA) was modified by a method of combining oxygen plasma treatment with anchorage of cationized gelatin. Modification effect of the method was compared with other methods of oxygen plasma treatment, cationized gelatin or gelatin coating and combining oxygen plasma treatment with anchorage of gelatin. The change of surface property was compared by contact angles, surface energy, X-ray photoelectron spectra (XPS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) measurement. The optimum oxygen pretreatment time determined by surface energy was 10 min when the power was 50 W and the oxygen pressure was 20 Pa. Analysis of the stability of gelatin and cationized gelatin anchored on PLGA by XPS, ATR-FTIR, contact angles and surface energy measurement indicated the cationized gelatin was more stable than gelatin. The result using mouse NIH 3T3 fibroblasts as model cells to evaluate cell affinity in vitro showed the cationized gelatin-anchored PLGA (OCG-PLGA) was more favorable for cell attachment and growth than oxygen plasma treated PLGA (O-PLGA) and gelatin-anchored PLGA (OG-PLGA). Moreover cell affinity of OCG-PLGA could match that of collagen-anchored PLGA (AC-PLGA). So the surface modification method combining oxygen plasma treatment with anchorage of cationized gelatin provides a universally effective way to enhance cell affinity of polylactone-type biodegradable polymers. PMID:17618682

  19. HIV antiretroviral drug combination induces endothelial mitochondrial dysfunction and reactive oxygen species production, but not apoptosis

    International Nuclear Information System (INIS)

    Numerous reports now indicate that HIV patients administered long-term antiretroviral therapy (ART) are at a greater risk for developing cardiovascular diseases. Endothelial dysfunction is an initiating event in atherogenesis and may contribute to HIV-associated atherosclerosis. We previously reported that ART induces direct endothelial dysfunction in rodents. In vitro treatment of human umbilical vein endothelial cells (HUVEC) with ART indicated endothelial mitochondrial dysfunction and a significant increase in the production of reactive oxygen species (ROS). In this study, we determined whether ART-induced endothelial dysfunction is mediated via mitochondria-derived ROS and whether this mitochondrial injury culminates in endothelial cell apoptosis. Two major components of ART combination therapy, a nucleoside reverse transcriptase inhibitor and a protease inhibitor, were tested, using AZT and indinavir as representatives for each. Microscopy utilizing fluorescent indicators of ROS and mitochondria demonstrated the mitochondrial localization of ART-induced ROS. MnTBAP, a cell-permeable metalloporphyrin antioxidant, abolished ART-induced ROS production. As a final step in confirming the mitochondrial origin of the ART-induced ROS, HUVEC were transduced with a cytosolic- compared to a mitochondria-targeted catalase. Transduction with the mitochondria-targeted catalase was more effective than cytoplasmic catalase in inhibiting the ROS and 8-isoprostane (8-iso-PGF2α) produced after treatment with either AZT or indinavir. However, both mitochondrial and cytoplasmic catalase attenuated ROS and 8-iso-PGF2α production induced by the combination treatment, suggesting that in this case, the formation of cytoplasmic ROS may also occur, and thus, that the mechanism of toxicity in the combination treatment group may be different compared to treatment with AZT or indinavir alone. Finally, to determine whether ART-induced mitochondrial dysfunction and ROS production culminate

  20. Effects of temperature and irradiance on a benthic microalgal community: A combined two-dimensional oxygen and fluorescence imaging approach

    DEFF Research Database (Denmark)

    Hancke, Kasper; Sorrell, Brian Keith; Lund-Hansen, Lars Chresten; Larsen, Morten; Hancke, Torunn; Glud, Ronnie

    2014-01-01

    The effects of temperature and light on both oxygen (O2) production and gross photosynthesis were resolved in a benthic microalgae community by combining two-dimensional (2D) imaging of O2 and variable chlorophyll a (Chl a) fluorescence. Images revealed a photosynthetically active community with...

  1. Pharyngeal oxygen administration increases the time to serious desaturation at intubation in acute lung injury: an experimental study

    OpenAIRE

    Engström, Joakim; Hedenstierna, Göran; Larsson, Anders

    2010-01-01

    Introduction Endotracheal intubation in critically ill patients is associated with severe life-threatening complications in about 20%, mainly due to hypoxemia. We hypothesized that apneic oxygenation via a pharyngeal catheter during the endotracheal intubation procedure would prevent or increase the time to life-threatening hypoxemia and tested this hypothesis in an acute lung injury animal model. Methods Eight anesthetized piglets with collapse-prone lungs induced by lung lavage were ventila...

  2. Blood oxygen flux estimation with a combined photoacoustic and high-frequency ultrasound microscopy system: a phantom study

    Science.gov (United States)

    Jiang, Yan; Forbrich, Alex; Harrison, Tyler; Zemp, Roger J.

    2012-03-01

    The metabolic rate of oxygen consumption, an important indicator of tissue metabolism, can be expressed as the change of net blood oxygen flux into and out of a tissue region per 100 g of tissue. In this work, we propose a photoacoustic and Doppler ultrasound method for imaging local blood oxygen flux of a single vessel. An imaging system for combined photoacoustic and high-frequency ultrasound microscopy is presented. This system uses a swept-scan 25-MHz ultrasound transducer with confocal dark-field laser illumination optics. A pulse-sequencer enables ultrasonic and laser pulses to be interlaced so that photoacoustic and Doppler ultrasound images are co-registered. Since the mean flow speed can be measured by color Doppler ultrasound, the vessel cross-sectional area can be measured by power Doppler or structural photoacoustic imaging, and multi-wavelength photoacoustic methods can be used to estimate oxygen saturation (sO2) and total concentration of haemoglobin (CHb), all of the parameters necessary for oxygen flux estimation can be provided. The accuracy of the flow speed and sO2 estimation has been investigated. In vitro sheep blood phantom experiments have been performed at different sO2 levels and mean flow speeds. Blood oxygen flux has been estimated, and the uncertainty of the measurement has been quantified.

  3. A therapeutic benefit from combining normobaric carbogen or oxygen with nicotinamide in fractionated X-ray treatments

    International Nuclear Information System (INIS)

    The ability of normobaric oxygen and carbogen (95 percent O2 + 5 percent CO2) combined with nicotinamide to enhance the radiosensitivity of two rodent adenocarcinomas and of mouse skin and kidneys was compared with the effects of radiation in air and without the drug. A comparison of the results in tumors and normal tissues showed that significant therapeutic benefit was obtained with normobaric oxygen and carbogen combined with nicotinamide. Toxic side effects of the treatment are unlikely, as prolonged administration of nicotinamide is well tolerated in man. The combination of normobaric carbogen with nicotinamide could be an effective method of enhancing tumor radiosensitivity in clinical radiotherapy where hypoxia limits the outcome of treatment. (author). 45 refs.; 4 fig.; 4 tabs

  4. The combined effects of additives and supports on the synthesis of oxygenates over supported rhodium

    International Nuclear Information System (INIS)

    There are potential advantages in the use of synthesis gas for the selective synthesis of oxygenated compounds rather than of hydrocarbons. This is due to the more versatile applications and higher value of oxygenates compared with that of hydrocarbons. Rh is known to be active in catalyzing, both heterogeneously and homogeneously, the formation of oxygenated compounds from synthesis gas. In a heterogeneous reaction system, the activity and selectivity of Rh catalysts are very sensitive to the chemical environment of Rh. By modifying its chemical environment through the use of various supports and/or with the addition of different promoters, Rh can selectively produce mostly oxygenates or mostly hydrocarbons. Studies have been carried out aimed at delineating the possible routes and intermediates involved in the formation of oxygenates and the function of additives (alkali promoters) and supports in the synthesis of oxygenates. Among the unpromoted Rh, the C/sub 2/ oxygenate selectivity decreased in the order: Rh/SiO/sub 2/ > Rh/MgO > Rh/La/sub 2/O/sub 3/ > Rh black, Rh/TiO/sub 2/ > Rh/Al/sub 2/O/sub 3/. High pressures improve selectivity to C/sub 2/ oxygenate compounds. Suppression of hydrogenation and ethanol dehydration was identified as major effects of alkali promotion. CO insertion was found to be dependent on both alkali promoters and on the supports. Results of ethanol addition indicated that the alkali species are located on both the Rh metal and on the support. The reaction network of CO hydrogenation on variously promoted catalysts is delineated, and the effect of secondary reactions on the overall product distribution is discussed

  5. Atomic oxygen dynamics in an air dielectric barrier discharge: a combined diagnostic and modeling approach

    Science.gov (United States)

    Baldus, Sabrina; Schröder, Daniel; Bibinov, Nikita; Schulz-von der Gathen, Volker; Awakowicz, Peter

    2015-06-01

    Cold atmospheric pressure plasmas are a promising alternative therapy for treatment of chronic wounds, as they have already shown in clinical trials. In this study an air dielectric barrier discharge (DBD) developed for therapeutic use in dermatology is characterized with respect to the plasma produced reactive oxygen species, namely atomic oxygen and ozone, which are known to be of great importance to wound healing. To understand the plasma chemistry of the applied DBD, xenon-calibrated two-photon laser-induced fluorescence spectroscopy and optical absorption spectroscopy are applied. The measured spatial distributions are shown and compared to each other. A model of the afterglow chemistry based on optical emission spectroscopy is developed to cross-check the measurement results and obtain insight into the dynamics of the considered reactive oxygen species. The atomic oxygen density is found to be located mostly between the electrodes with a maximum density of {{n}\\text{O}}=6× {{10}16} cm-3 . Time resolved measurements reveal a constant atomic oxygen density between two high voltage pulses. The ozone is measured up to 3 mm outside the active plasma volume, reaching a maximum value of {{n}{{\\text{O}3}}}=3× {{10}16} cm-3 between the electrodes.

  6. ENZYMATIC BLEACHING OF COTTON FIBRES WITH LACCASE/MEDIATOR SYSTEMS COMBINED WITH OXYGEN AND OZONE

    Directory of Open Access Journals (Sweden)

    Tuba İNKAYA

    2008-01-01

    Full Text Available Enzymes should be used in every step of pretreatment of cotton textiles in order to minimize energy and water consumption while keeping the effluent control within the tolerable standards. It has been investigated whether enzymatic bleaching of cotton textiles could be replaced with hydrogen peroxide bleaching, which is a water and energy consuming step. In this study, fungal laccase, laccase moderator systems and also oxygen and ozone feed to these systems have been experimented. The initial whiteness of the desizied fabric before bleaching was 49 stensby degree. This value did not increase over 51 stensby degree by use of enzyme and also enzyme moderator systems. Oxygen and ozone feeding at a gas flow rate of 1000 ml/min and ozone concentration of 32 mg/min have been conducted in order to increase whiteness. Oxygen feed did not have a considerable effect and whiteness degrees raised up to only 51 stensby degree, however, ozone feed enhanced to raise the whiteness of the fabric upto 68 stensby degree by enzyme alone and 70 stensby degree by enzyme moderator systems.

  7. Monitoring cancer treatment response using photoacoustic and ultrasound spectral analysis in combination with oxygenation measurements (Conference Presentation)

    Science.gov (United States)

    Hysi, Eno; May, Jonathan P.; Wirtzfeld, Lauren; Undzys, Elijus; Li, Shyh-Dar; Kolios, Michael C.

    2016-03-01

    At clinically-relevant depths, the frequency content of photoacoustic signals encodes information about the size, concentration and spatial distribution of non-resolvable blood vessels. This study evaluates whether photoacoustics can detect cancer therapy-induced vascular perturbations. Photoacoustic/ultrasound (PA/US) spectral analysis was combined with functional, PA-based oxygenation and power Doppler (PD) perfusion estimates to assess treatment response. Co-registered, in-vivo US/PA/PD imaging of mice bearing breast cancer tumors was performed pre-treatment and 30m/2h/5h/24h/7d post-treatment (VevoLAZR, Fujifilm VisualSonics). Hyperthermia treatment (1h, 43C) was performed after systemic injections of doxorubicin-loaded thermosensitive liposomes (TSL, n=13) or free doxorubicin (DOX, n=11). Response was classified according to 2h, PA-based oxygenation drop and endpoint (>9d), caliper-based volume reduction. At all time-points/wavelengths (750/850nm), the spectral-slope (SS) was computed from the normalized US/PA power spectra using depth-matched reference phantoms. The percent-vascularity (PV) was estimated for the animal with the largest oxygenation-drop at 2h. TLS-treated responders decreased their PA-SS by 1.9x @750nm and 5.8x @850nm 30m post-treatment and remained constant for 24h; tumor oxygenation followed the same trend. Non-responding SS remained unchanged for 24h. The 750nm SS was 18.7x lower than 850nm suggesting the TSL is sensitive vessel oxygenation. Responder PV decreased 100% when the 30m oxygenation dropped 15% and increased 7x when the 7d oxygenation increased 20%. DOX-responders exhibited similar trends to TSL-responders although the 750nm PA-SS was 1.6x smaller and post-treatment PV was 50% higher. The US-SS remained unchanged until 7d post-treatment suggesting its sensitivity to tumor cell-death. These findings suggest that PA spectral analysis has potential in monitoring cancer treatment response.

  8. Effect of nicardipine combined with esmolol on systemic and tissue oxygenation during off-pump coronary artery bypass grafting surgery

    Institute of Scientific and Technical Information of China (English)

    WANG Tian-long; JIANG Yan; YANG Ba-xian

    2005-01-01

    Background The hemodynamics and oxygenation severely fluctuated during the off-pump coronary artery bypass grafting (OPCABG). This study aimed at investigating whether or not nicardipine combined with esmolol (1∶ 10) can maintain systemic and tissue oxygenation during OPCABG.Methods Twenty patients scheduled for OPCABG were divided ramdomly into Group nicardipine (N) and Group nitroglycerine (X) respectively combined with esmolol (E) (Dosage ratio: 1 to 10) (Group N+E and Group X+E) with 10 patients in each group. The mixed solution of N+E or X+E were titrated to maintain mean arterial blood pressure between 70 and 80 mmHg following anesthesia induction. The variables of hemodynamics, arterial blood lactate content (Lac) and gastric intramucosal partial pressure of carbon dioxide were measured at the following time points: after induction of anesthesia (T1), pre-revascularization (T2), grafting of left anterior descending (T3), right coronary descending (T4) and left coronary circumflexus branches (T5), post-revascularization (T6), the end of operation (T7). The delivery of oxygen (DO2), consumption of oxygen (VO2) and gastric intramucosal pH (pHi) were calculated.Results The cardiac index (CI) in Group N+E was significantly increased (P<0.05) as compared with T1 during OPCABG, while it was mildly decreased in Group X+E. The stroke volumes at T4, T5 in Group N+E and at T3-T6 in Group X+E were significantly decreased (P<0.05). The systemic vascular resistance indices in Group N+E were significantly decreased as compared with T1 (P<0.05). The heart rates in these two Groups were significantly elevated intraoperatively (P<0.05). The DO2 after the infusion of N+E was significantly increased (P<0.05) or leveled to T1, and the Lac were within the normal range. But the DO2 in Group X+E was decreased throughout the procedure, reaching significant level at T5 (P<0.05), and the Lac was significantly increased beyond normal range (P<0.05). The pHi in Group N+E was

  9. Effect of mesenchymal stem cells transplantation combining with hyperbaric oxygen therapy on rehabilitation of rat spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Cheng-Kui Geng; Hong-Hua Cao; Xiong Ying; Hua-Lin Yu

    2015-01-01

    Objective:To investigate the effect of BMSCs transplantation plus hyperbaric oxygen (HBO) on repair of rat SCI. Methods:Seventy five male rats were divided randomly into five groups:sham, vehicle, BMSCs transplantation group, combination group, 15 rats in each group. Every week after the SCI onset, all animals were evaluated for behavior outcome by Basso-Beattle-Bresnahan (BBB) score and inclined plane test. Axon recovery was examined with focal spinal cord tissue by electron microscope at 6 weeks after the SCI onset. HE staining and BrdU staining were performed to examine the BMSCs and lesion post injury. Somatosensory evoked potential (SEP) testing was performed to detect the recovery of neural conduction. Results:Results from the behavior tests from combination group were significant higher than rats which received only transplantation or HBO treatment. Results from histopathology showed favorable recovery from combination group than other treatment groups. The number of BrdU+ in combination group were measureable more than transplantation group (P<0.05). The greatest decrease in TNF-α, IL-1β, IL-6, IFN-αdetermined by Elisa assay in combination group were evident too. Conclusions:BMSCs transplantation can promote the functional recovery of rat hind limbs after SCI, and its combination with HBO has a synergistic effect.

  10. Effect of mesenchymal stem cells transplantation combining with hyperbaric oxygen therapy on rehabilitation of rat spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Cheng-Kui; Geng; Hong-Hua; Cao; Xiong; Ying; Hua-Lin; Yu

    2015-01-01

    Objective:To investigate the effect of BMSCs transplantation plus hyperbaric oxygen(HBO)on repair of rat SCI.Methods:Seventy five male rats were divided randomly into five groups:sham,vehicle.BMSCs transplantation group,combination group,15 rats in each group.Every week after the SCI onset,all animals were evaluated for behavior outcome by Basso-BeattleBresnahan(BBB) score and inclined plane test.Axon recovery was examined with focal spinal cord tissue by electron microscope at 6 weeks after the SCI onset.HE staining and BrdU staining were performed to examine the BMSCs and lesion post injury.Somatosensory evoked potential(SEP) testing was performed to detect the recovery of neural conduction.Results from the behavior tests from combination group were significant higher than rats which received only transplantation or HBO treatment.Results from histopathology showed favorable recovery from combination group than other treatment groups.The number of BrdU+ in combination group were measureable more than transplantation group(P<0.05).The greatest decrease in TNF-α,IL-1β,IL-6.IFN-α determined by Elisa assay in combination group were evident too.Conclusions:BMSCs transplantation can promote the functional recovery of rat hind limbs after SCI,and its combination with HBO has a synergistic effect.

  11. Serum indicators and endothelial function of hyperbaric oxygen combined with memantine and Aricept treatment of senile vascular dementia

    Institute of Scientific and Technical Information of China (English)

    Yao-Yi Yin

    2016-01-01

    Objective:To find the effect of hyperbaric oxygen combined with memantine and Aricept treatment of senile vascular dementia on serum indicators and endothelial function.Methods:A total of126 cases of patients with senile vascular dementia treated in our hospital from March 2012 to December 2014 were selected as research subjects, treatment that patients received was retrospectively analyzed, and patients were divided into observation group 64 cases and control group 62 cases. Control group received memantine and Aricept therapy, observation group received hyperbaric oxygen combined with memantine and Aricept therapy, and then differences in levels of serum TGF-β, IGF-1 and ICAM-1, Hcy, MDA and SOD, NPY, sFas, sFasL and so on, ET and EPC between two groups were compared.Results:Serum TGF-β ad IGF-1 levels of observation group after treatment were higher than those of control group, and ICAM-1 levels were lower than those of control group; Hcy and MDA levels of observation group after treatment were lower than those of control group at corresponding points in time, and SOD levels were higher than those of control group; serum NPY, sFas, sFasL and Ca2+ values of observation group after treatment were lower than those of control group, and PON-1 value was higher than that of control group; ET values of observation group at various points in time after treatment were lower than those of control group, and EPC contents were higher than those of control group.Conclusion:Hyperbaric oxygen combined with memantine and Aricept treatment for patients with senile vascular dementia can effectively improve the disease and optimize endothelial function, and it has active clinical significance.

  12. Percutaneous treatment of non-contained lumbar disc herniation by injection of oxygen-ozone combined with collagenase

    Energy Technology Data Exchange (ETDEWEB)

    Wu Zhiqun [Therapy Center of Pain, Division of Interventional Radiology, Tang Du Hospital, Fourth Military Medical University, Xian 710038 (China)], E-mail: zhiqunwu@yahoo.com; Wei Longxiao [Therapy Center of Pain, Division of Interventional Radiology, Tang Du Hospital, Fourth Military Medical University, Xian 710038 (China); Li Jun [Therapy Center of Pain, Division of Orthopedic Surgery, Tang Du Hospital, Fourth Military Medical University, Xian 710038 (China); Wang Yiqing; Ni Daihui [Therapy Center of Pain, Division of Interventional Radiology, Tang Du Hospital, Fourth Military Medical University, Xian 710038 (China); Yang Peng; Zhang Yuhai [Department of Biostatistics, Fourth Military Medical University, Xian 710032 (China)

    2009-12-15

    Purpose: To evaluate the therapeutic results of oxygen-ozone combined collagenase injection for the treatment of lumbar disc herniation compared to the surgery. And to explore the role of this minimally invasive treatment as an alternative to disc surgery. Materials and methods: Two groups of patients (n = 108) were treated with different ways respectively. Minimally invasive group of patients was treated with the injection of oxygen-ozone combined with collagenase into the lumbar disc or the epidural space; the other group was treated with traditional surgery. After the treatment, the patients were followed-up and the therapeutic effect was assessed at 2 weeks, 3 and 12 months by the modified Macnab criteria. Results: The success rate was 86.11% and 88.89% in minimally invasive group at 3 and 12 months respectively, while 92.59% and 95.37% in surgical group. There was no statistically significant difference between two groups at 3 and 12 months (P = 0.123, P = 0.08). However, the surgical group produced a statistically significant greater improvement for back pain and disability in the first few weeks (P = 0.0001). The success rate was 51.86% and 85.18% at 2 weeks in minimally invasive group and surgical group respectively. No serious complication occurred in this group. Conclusions: The combination of the oxygen-ozone with collagenase shows significant reductions in pain and improvements in function at 3 and 12 months, it can be considered as an option for the treatment of non-contained lumbar disc herniation instead of surgery.

  13. Kinetics of oxygen reduction in perovskite cathodes for solid oxide fuel cells: A combined modeling and experimental approach

    Science.gov (United States)

    Miara, Lincoln James

    Solid oxide fuel cells (SOFCs) have the potential to replace conventional stationary power generation technologies; however, there are major obstacles to commercialization, the most problematic of which is poor cathode performance. Commercialization of SOFCs will follow when the mechanisms occurring at the cathode are more thoroughly understood and adapted for market use. The catalytic reduction of oxygen occurring in SOFC cathodes consists of many elementary steps such as gas phase diffusion, chemical and/or electrochemical reactions which lead to the adsorption and dissociation of molecular oxygen onto the cathode surface, mass transport of oxygen species along the surface and/or through the bulk of the cathode, and full reduction and incorporation of the oxygen at the cathode/electrolyte two or three phase boundary. Electrochemical impedance spectroscopy (EIS) is the main technique used to identify the occurrence of these different processes, but when this technique is used without an explicit model describing the kinetics it is difficult to unravel the interdependence of each of these processes. The purpose of this dissertation is to identify the heterogeneous reactions occurring at the cathode of an SOFC by combining experimental EIS results with mathematical models describing the time dependent behavior of the system. This analysis is performed on two different systems. In the first case, experimental EIS results from patterned half cells composed of Ca-doped lanthanum manganite (LCM)| yttria-doped ZrO2 (YSZ) are modeled to investigate the temperature and partial pressure of oxygen, pO2, dependence of oxygen adsorption/dissociation onto the LCM surface, surface diffusion of atomic oxygen, and electrochemical reduction and incorporation of the oxygen into the electrolyte in the vicinity of the triple phase boundary (TPB). This model determines the time-independent state-space equations from which the Faradaic admittance transfer function is obtained. The

  14. Combination therapy of normobaric oxygen with hypothermia or ethanol modulates pyruvate dehydrogenase complex in thromboembolic cerebral ischemia.

    Science.gov (United States)

    Cai, Lipeng; Thibodeau, Alexa; Peng, Changya; Ji, Xunming; Rastogi, Radhika; Xin, Ruiqiang; Singh, Sunpreet; Geng, Xiaokun; Rafols, Jose A; Ding, Yuchuan

    2016-08-01

    Pyruvate dehydrogenase complex (PDH) is a brain mitochondrial matrix enzyme. PDH impairment after stroke is particularly devastating given PDH's critical role in the link between anaerobic and aerobic metabolism. This study evaluates the restoration of oxidative metabolism and energy regulation with a therapeutic combination of normobaric oxygen (NBO) plus either therapeutic hypothermia (TH) or ethanol. Sprague-Dawley rats were subjected to middle cerebral artery occlusion with an autologous embolus. One hour after occlusion, tissue-type plasminogen activator (t-PA) was administered alone or with NBO (60%), EtOH (1.0 g/kg), or TH (33°C), either singly or in combination. Neurological deficit score and infarct volume were assessed 24 hr after t-PA-induced reperfusion. PDH activity and reactive oxygen species (ROS) levels were measured 3 and 24 hr after t-PA. Western blotting was used to detect PDH and pyruvate dehydrogenase kinase (PDK) protein expression. After t-PA in ischemic rats, NBO combined with TH or EtOH most effectively decreased infarct volume and neurological deficit. The combined therapies produced greater increases in PDH activity and protein expression as well as greater decreases in PDK expression. Compared with the monotherapeutic approaches, the combined therapies provided the most significant declines in ROS generation. Reperfusion with t-PA followed by 60% NBO improves the efficacy of EtOH or TH in neuroprotection by ameliorating oxidative injury and improving PDH regulation. Comparable neuroprotective effects were found when treating with either EtOH or TH, suggesting a similar mechanism of neuroprotection and the possibility of substituting EtOH for TH in clinical settings. © 2016 Wiley Periodicals, Inc. PMID:27027410

  15. Combined effect of nitrogen- and oxygen-containing functional groups of microporous activated carbon on its electrochemical performance in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Hulicova-Jurcakova, Denisa; Lu, Gao Qing [University of Queensland ARC, Centre of Excellence for Functional Nanomaterials Australian Institute for Bioengineering and Nanotechnology and School of Engineering Corner College, St Lucia (Australia); Seredych, Mykola; Bandosz, Teresa J. [City College of New York, Department of Chemistry, New York, NY (United States)

    2009-02-10

    Microporous activated carbon originating from coconut shell, as received or oxidized with nitric acid, is treated with melamine and urea and heated to 950 C in an inert atmosphere to modify the carbon surface with nitrogen- and oxygen-containing groups for a systematic investigation of their combined effect on electrochemical performance in 1 M H{sub 2}SO{sub 4} supercapacitors. The chemistry of the samples is characterized using elemental analysis, Boehm titration, potentiometric titration, and X-ray photoelectron spectroscopy. Sorption of nitrogen and carbon dioxide is used to determine the textural properties. The results show that the surface chemistry is affected by the type of nitrogen precursor and the specific groups present on the surface before the treatment leading to the incorporation of nitrogen. Analysis of the electrochemical behavior of urea- and melamine-treated samples reveal pseudocapacitance from both the oxygen and the nitrogen containing functional groups located in the pores larger than 10A. On the other hand, pores between 5A and 6A are most effective in a double-layer formation, which correlates well with the size of hydrated ions. Although the quaternary and pyridinic-N-oxides nitrogen groups have enhancing effects on capacitance due to the positive charge, and thus an improved electron transfer at high current loads, the most important functional groups affecting energy storage performance are pyrrolic and pyridinic nitrogen along with quinone oxygen. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  16. Barley responses to combined waterlogging and salinity stress: separating effects of oxygen deprivation and elemental toxicity.

    Science.gov (United States)

    Zeng, Fanrong; Shabala, Lana; Zhou, Meixue; Zhang, Guoping; Shabala, Sergey

    2013-01-01

    Salinity and waterlogging are two major factors affecting crop production around the world and often occur together (e.g., salt brought to the surface by rising water tables). While the physiological and molecular mechanisms of plant responses to each of these environmental constraints are studied in detail, the mechanisms underlying plant tolerance to their combined stress are much less understood. In this study, whole-plant physiological responses to individual/combined salinity and waterlogging stresses were studied using two barley varieties grown in either vermiculite (semi-hydroponics) or sandy loam. Two weeks of combined salinity and waterlogging treatment significantly decreased plant biomass, chlorophyll content, maximal quantum efficiency of PSII and water content (WC) in both varieties, while the percentage of chlorotic and necrotic leaves and leaf sap osmolality increased. The adverse effects of the combined stresses were much stronger in the waterlogging-sensitive variety Naso Nijo. Compared with salinity stress alone, the combined stress resulted in a 2-fold increase in leaf Na(+), but a 40% decrease in leaf K(+) content. Importantly, the effects of the combined stress were more pronounced in sandy loam compared with vermiculite and correlated with changes in the soil redox potential and accumulation of Mn and Fe in the waterlogged soils. It is concluded that hypoxia alone is not a major factor determining differential plant growth under adverse stress conditions, and that elemental toxicities resulting from changes in soil redox potential have a major impact on genotypic differences in plant physiological and agronomical responses. These results are further discussed in the context of plant breeding for waterlogging stress tolerance. PMID:23967003

  17. Combined Carbon, Nitrogen, and Oxygen XANES Spectroscopy on Hydrated and Anhydrous Interplanetary Dust Particles

    Science.gov (United States)

    Feser, M.; Wirick, S.; Flynn, G. J.; Keller, L. P.

    2003-01-01

    Interplanetary dust particles (IDPs) collected from the Earth s stratosphere generally contain percent-level concentrations of organic matter. This organic matter in IDPs is important for several reasons: 1) some IDPs contain interstellar organic matter, identified by high D/H or N-15, providing the opportunity to characterize this interstellar material, 2) comparison of the organic matter in anhydrous IDPs to that in hydrated IDPs can help establish the effects of parent body aqueous alteration, and, 3) IDPs are believed to have delivered to the surface of the early Earth pre-biotic organic matter important for the origin of life. X-Ray Absorption Near-Edge Structure (XANES) spectroscopy provides information on the functional groups present in a sample, and XANES can be performed on the nano-scale, comparable to the size of some of the sub-units of the IDPs. The energies of the XANES transitions are diagnostic of the type of bonding of the C, N, and O, allowing identification of the functional groups present in the sample. As part of our ongoing effort to characterize the organic matter in the IDPs, we have performed carbon- and oxygen- and the first nitrogen-XANES spectroscopy on two IDPs and acid-insoluble residue from the CM2 meteorite Murchison.

  18. Patterning Poly(dimethylsiloxane) Microspheres via Combination of Oxygen Plasma Exposure and Solvent Treatment.

    Science.gov (United States)

    Li, Qiaoyuan; Han, Xue; Hou, Jing; Yin, Jian; Jiang, Shichun; Lu, Conghua

    2015-10-22

    Here a simple low-cost yet robust route has been developed to prepare poly(dimethylsiloxane) (PDMS) microspheres with various surface wrinkle patterns. First, the aqueous-phase-synthesized PDMS microspheres are exposed to oxygen plasma (OP), yielding the oxidized SiOx layer and the corresponding stiff shell/compliant core system. The subsequent solvent swelling and solvent evaporation induce the spontaneous formation of a series of curvature and overstress-sensitive spherical wrinkles such as dimples, short rodlike depressions, and herringbone and labyrinth patterns. The effects of the experimental parameters, including the radius and Young's modulus of the microspheres, the OP exposure duration, and the nature of the solvents, on these tunable spherical wrinkles have been systematically studied. The experimental results reveal that a power-law dependence of the wrinkling wavelength on the microsphere radius exists. Furthermore, the induced wrinkling patterns are inherently characteristic of a memory effect and good reversibility. Meanwhile, the corresponding phase diagram of the wrinkle morphologies on the spherical surfaces vs the normalized radius of curvature and the excess swelling degree has been demonstrated. It is envisioned that the introduced strategy in principle could be applied to other curved surfaces for expeditious generation of well-defined wrinkle morphologies, which not only enables the fabrication of solids with multifunctional surface properties, but also provides important implications for the morphogenesis in soft materials and tissues. PMID:26435184

  19. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Hai-xiao Zhou; Zhi-gang Liu; Xiao-jiao Liu; Qian-xue Chen

    2016-01-01

    Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO) treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized lfuid (2.5–3.0 atm impact force). The injured rats were then administered UC-MSC transplantationvia the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function signiifcantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and signiifcantly promotes recovery of neurological functions.

  20. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Hai-xiao Zhou

    2016-01-01

    Full Text Available Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid (2.5-3.0 atm impact force. The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions.

  1. Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury.

    Science.gov (United States)

    Zhou, Hai-Xiao; Liu, Zhi-Gang; Liu, Xiao-Jiao; Chen, Qian-Xue

    2016-01-01

    Transplantation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen (HBO) treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid (2.5-3.0 atm impact force). The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions. PMID:26981097

  2. Combined sonodynamic and antimetabolite therapy for the improved treatment of pancreatic cancer using oxygen loaded microbubbles as a delivery vehicle.

    Science.gov (United States)

    McEwan, Conor; Kamila, Sukanta; Owen, Joshua; Nesbitt, Heather; Callan, Bridgeen; Borden, Mark; Nomikou, Nikolitsa; Hamoudi, Rifat A; Taylor, Mark A; Stride, Eleanor; McHale, Anthony P; Callan, John F

    2016-02-01

    In this manuscript we describe the preparation of an oxygen-loaded microbubble (O2MB) platform for the targeted treatment of pancreatic cancer using both sonodynamic therapy (SDT) and antimetabolite therapy. O2MB were prepared with either the sensitiser Rose Bengal (O2MB-RB) or the antimetabolite 5-fluorouracil (O2MB-5FU) attached to the microbubble (MB) surface. The MB were characterised with respect to size, physical stability and oxygen retention. A statistically significant reduction in cell viability was observed when three different pancreatic cancer cell lines (BxPc-3, MIA PaCa-2 and PANC-1), cultured in an anaerobic cabinet, were treated with both SDT and antimetabolite therapy compared to either therapy alone. In addition, a statistically significant reduction in tumour growth was also observed when ectopic human xenograft BxPC-3 tumours in SCID mice were treated with the combined therapy compared to treatment with either therapy alone. These results illustrate not only the potential of combined SDT/antimetabolite therapy as a stand alone treatment option in pancreatic cancer, but also the capability of O2-loaded MBs to deliver O2 to the tumour microenvironment in order to enhance the efficacy of therapies that depend on O2 to mediate their therapeutic effect. Furthermore, the use of MBs to facilitate delivery of O2 as well as the sensitiser/antimetabolite, combined with the possibility to activate the sensitiser using externally applied ultrasound, provides a more targeted approach with improved efficacy and reduced side effects when compared with conventional systemic administration of antimetabolite drugs alone. PMID:26702983

  3. Combination therapy with normobaric oxygen (NBO plus thrombolysis in experimental ischemic stroke

    Directory of Open Access Journals (Sweden)

    Singhal Aneesh B

    2009-07-01

    Full Text Available Abstract Background The widespread use of tissue plasminogen activator (tPA, the only FDA-approved acute stroke treatment, remains limited by its narrow therapeutic time window and related risks of brain hemorrhage. Normobaric oxygen therapy (NBO may be a useful physiological strategy that slows down the process of cerebral infarction, thus potentially allowing for delayed or more effective thrombolysis. In this study we investigated the effects of NBO started simultaneously with intravenous tPA, in spontaneously hypertensive rats subjected to embolic middle cerebral artery (MCA stroke. After homologous clot injection, animals were randomized into different treatment groups: saline injected at 1 hour; tPA at 1 hour; saline at 1 hour plus NBO; tPA at 1 hour plus NBO. NBO was maintained for 3 hours. Infarct volume, brain swelling and hemorrhagic transformation were quantified at 24 hours. Outcome assessments were blinded to therapy. Results Upon clot injection, cerebral perfusion in the MCA territory dropped below 20% of pre-ischemic baselines. Both tPA-treated groups showed effective thrombolysis (perfusion restored to nearly 100% and smaller infarct volumes (379 ± 57 mm3 saline controls; 309 ± 58 mm3 NBO; 201 ± 78 mm3 tPA; 138 ± 30 mm3 tPA plus NBO, showing that tPA-induced reperfusion salvages ischemic tissue and that NBO does not significantly alter this neuroprotective effect. NBO had no significant effect on hemorrhagic conversion, brain swelling, or mortality. Conclusion NBO can be safely co-administered with tPA. The efficacy of tPA thrombolysis is not affected and there is no induction of brain hemorrhage or edema. These experimental results require clinical confirmation.

  4. Enhanced phosphorus removal from wastewater by growing deep-sea bacterium combined with basic oxygen furnace slag.

    Science.gov (United States)

    Zhou, Weizhi; Huang, Zhaosong; Sun, Cuiping; Zhao, Haixia; Zhang, Yuzhong

    2016-08-01

    As one solid waste with potential for phosphorus removal, application of slags in water treatment merits attention. But it was inhibited greatly by alkaline solution (pH>9.5) and cemented clogging generated. To give one solution, phosphorus removal was investigated by combining deep-sea bacterium Alteromonas 522-1 and basic oxygen furnace slag (BOFS). Results showed that by the combination, not only higher phosphorous removal efficiency (>90%) but also neutral solution pH of 7.8-8.0 were achieved at wide ranges of initial solution pH value of 5.0-9.0, phosphorus concentration of 5-30mg/L, salinity of 0.5-3.5%, and temperature of 15-35°C. Moreover, sedimentary property was also improved with lower amount of sludge production and alleviated BOFS cementation with increased porosity and enlarged particle size. These results provided a promising strategy for the phosphorus recovery with slags in large-scale wastewater treatment. PMID:27179297

  5. Hydration of mantle olivine under variable water and oxygen fugacity conditions: a combined SIMS and FTIR study

    Science.gov (United States)

    Gaetani, G. A.; O'Leary, J. A.; Koga, K. T.; Hauri, E. H.; Rose-Koga, E. F.

    2012-12-01

    Trace concentrations of H+ dissolved in peridotite strongly affect both its rheology and solidus. Olivine comprises ~70% of a peridotite mode and is capable of incorporating substantial H+ at upper mantle conditions. Recently, Grant et al. (2007) conducted olivine hydration experiments to determine the influence of oxygen fugacity on H+ incorporation. FTIR analyses of their run products show that absorption bands at 3325 and 3355 cm-1 (Group II bands of Bai and Kohlstedt (1993)) are sensitive to oxygen fugacity and, therefore, likely correspond to Fe3+-bearing point defects. New olivine hydration experiments were conducted to quantify H+ concentration changes associated with these defects. SIMS was used to quantify the H+ concentration and FTIR analyses were used to monitor changes in point defect populations. Our results agree with those of Grant et al. (2007) that Group II absorption bands are sensitive to fO2, but SIMS analyses indicate that changing oxygen fugacity from Fe-Fe1-XO to Ni-NiO at constant P, T and olivine composition only increases the concentration of H+ by ~50%. Olivine hydration experiments were conducted at 1.0, 1.5, or 2.0 GPa and 1200 °C using a piston cylinder device. Oxygen fugacity was controlled at the Fe-Fe1-XO, Fe1-XO-Fe3O4, or Ni-NiO buffer. Mixed H2O-CO2 experiments were used to resolve the influence of P from that of H2O fugacity. Starting materials, fabricated from large single crystals of San Carlos olivine (Fo88-91), were pressure-sealed in either a Fe0 or Ni0 capsule. The H+ concentration of run products were measured using a Cameca 6F ion microprobe and the protocols of Koga et al. (2003). Total infrared absorption spectra were determined by a combined polarized absorption spectra taken at three orthogonal orientation, roughly parallel to crystallographic orientation. Spectra were taken on single crystal olivines shaped as parallelapipeds with several 100s of micron thicknesses. Results from our experiments confirm that H2O

  6. Effect of ambient combinations of argon, oxygen, and hydrogen on the properties of DC magnetron sputtered indium tin oxide films

    International Nuclear Information System (INIS)

    Sputtering has been well-developed industrially with singular ambient gases including neutral argon (Ar), oxygen (O2), hydrogen (H2) and nitrogen (N2) to enhance the electrical and optical performances of indium tin oxide (ITO) films. Recent preliminary investigation into the use of combined ambient gases such as an Ar+O2+H2 ambient mixture, which was suitable for producing high-quality (low sheet resistance and high optical transmittance) of ITO films. To build on this promising preliminary work and develop deeper insight into the effect of ambient atmospheres on ITO film growth, this study provides a more detailed investigation of the effects of ambient combinations of Ar, O2, H2 on sputtered ITO films. Thin films of ITO were deposited on glass substrates by DC magnetron sputtering using three different ambient combinations: Ar, Ar+O2 and Ar+O2+H2. The structural, electrical and optical properties of the three ambient sputtered ITO films were systematically characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, four probe electrical conductivity and optical spectroscopy. The XRD and Raman studies confirmed the cubic indium oxide structure, which is polycrystalline at room temperature for all the samples. AFM shows the minimum surface roughness of 2.7 nm for Ar+O2+H2 sputtered thin film material. The thickness of the films was determined by the cross sectional SEM analysis and its thickness was varied from 920 to 817 nm. The columnar growth of ITO films was also discussed here. The electrical and optical measurements of Ar+O2+H2 ambient combinations shows a decreased sheet resistance (5.06 ohm/□) and increased optical transmittance (69%) than other samples. The refractive index and packing density of the films were projected using optical transmission spectrum. From the observed results the Ar+O2+H2 ambient is a good choice to enhance the total optoelectronic properties of the ITO films

  7. Effect of ambient combinations of argon, oxygen, and hydrogen on the properties of DC magnetron sputtered indium tin oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Marikkannan, M. [Department of Materials Science, School of Chemistry, Madurai Kamaraj University, Tamil Nadu, Madurai-625021 (India); Subramanian, M.; Tanemura, M. [Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Mayandi, J., E-mail: pearce@mtu.edu, E-mail: jeyanthinath@yahoo.co.in [Department of Materials Science, School of Chemistry, Madurai Kamaraj University, Tamil Nadu, Madurai-625021 (India); Department of Materials Science and Engineering, Michigan Technological University (United States); Vishnukanthan, V. [Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1126 Blindern, N-0318 Oslo (Norway); Pearce, J. M., E-mail: pearce@mtu.edu, E-mail: jeyanthinath@yahoo.co.in [Department of Materials Science and Engineering, Michigan Technological University (United States); Department of Electrical and Computer Engineering, Michigan Technological University (United States)

    2015-01-15

    Sputtering has been well-developed industrially with singular ambient gases including neutral argon (Ar), oxygen (O{sub 2}), hydrogen (H{sub 2}) and nitrogen (N{sub 2}) to enhance the electrical and optical performances of indium tin oxide (ITO) films. Recent preliminary investigation into the use of combined ambient gases such as an Ar+O{sub 2}+H{sub 2} ambient mixture, which was suitable for producing high-quality (low sheet resistance and high optical transmittance) of ITO films. To build on this promising preliminary work and develop deeper insight into the effect of ambient atmospheres on ITO film growth, this study provides a more detailed investigation of the effects of ambient combinations of Ar, O{sub 2}, H{sub 2} on sputtered ITO films. Thin films of ITO were deposited on glass substrates by DC magnetron sputtering using three different ambient combinations: Ar, Ar+O{sub 2} and Ar+O{sub 2}+H{sub 2}. The structural, electrical and optical properties of the three ambient sputtered ITO films were systematically characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, four probe electrical conductivity and optical spectroscopy. The XRD and Raman studies confirmed the cubic indium oxide structure, which is polycrystalline at room temperature for all the samples. AFM shows the minimum surface roughness of 2.7 nm for Ar+O{sub 2}+H{sub 2} sputtered thin film material. The thickness of the films was determined by the cross sectional SEM analysis and its thickness was varied from 920 to 817 nm. The columnar growth of ITO films was also discussed here. The electrical and optical measurements of Ar+O{sub 2}+H{sub 2} ambient combinations shows a decreased sheet resistance (5.06 ohm/□) and increased optical transmittance (69%) than other samples. The refractive index and packing density of the films were projected using optical transmission spectrum. From the observed results the Ar+O{sub 2}+H

  8. Relative humidity across the Paleocene-Eocene Thermal Maximum via combined hydrogen-oxygen isotope paleohygrometry (Invited)

    Science.gov (United States)

    McInerney, F. A.; Bloch, J. I.; Secord, R.; Wing, S. L.; Kraus, M. J.; Boyer, D. M.

    2009-12-01

    The Paleocene-Eocene Thermal Maximum (PETM) presents an opportunity to characterize continental hydrologic changes during rapid and extreme global warming. The Bighorn Basin, Wyoming, USA, has long been recognized for the PETM sequences preserved there and sits in an ideal location for recording hydrologic changes in the interior of North America. The southeast Bighorn Basin is of particular interest because it contains not only alluvial paleosols and vertebrate fossils, but also macrofloral remains from the PETM. The carbon isotope excursion associated with this event is preserved in this part of the Basin in leaf wax lipids, tooth enamel, and bulk organic matter. To characterize the hydrologic changes that occurred during the PETM we are applying a suite of isotopic, paleobotanical and paleopedological approaches to sections in the southeast Bighorn Basin. Reported here are results from the combined hydrogen and oxygen isotope analysis aimed at reconstructing relative humidity. Oxygen isotope ratios (δ18O) of biogenic apatite from mammalian tooth enamel and fish scales vary with environment, physiology and diet. Because mammals are homeothermic, they primarily track surface water values with predictable physiological offsets. Hydrogen isotope ratios (δD) of leaf-wax lipids (long-chain n-alkanes) reflect both meteoric water δD values and additional D-enrichment caused by evapotranspiration. The enrichment factor between water δD and n-alkane δD can therefore be used as a proxy for relative humidity (RH). In this study, δ18O of surface water is estimated using the δ18O of Coryphodon tooth enamel. We use these δ18O values to estimate surface water δD values using the Global Meteoric Water Line (δD = 8δ18O + 10). We then calculate relative humidity from n-alkane δD values using a Craig-Gordon type isotopic model for D-enrichment caused by transpiration from leaves. Results of the combined hydrogen-oxygen isotope paleohygrometer indicate a general rise in

  9. Simultaneous blood flow and blood oxygenation measurements using a combination of diffuse speckle contrast analysis and near-infrared spectroscopy

    Science.gov (United States)

    Seong, Myeongsu; Phillips, Zephaniah; Mai, Phuong Minh; Yeo, Chaebeom; Song, Cheol; Lee, Kijoon; Kim, Jae Gwan

    2016-02-01

    A combined diffuse speckle contrast analysis (DSCA)-near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times (<1 ms) show a higher drop (between 50% and 66%) and recovery of 1/KS2 values after occlusion (approximately 150%), but longer exposure time (3 ms) shows more consistent hemodynamic changes. For four subjects, the 1/KS2 values dropped to an average of 82.1±4.0% during the occlusion period and the average recovery of 1/KS2 values after occlusion was 109.1±0.8%. There was also an approximately equivalent amplitude change in oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=-0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.

  10. High performance SOFC/GT combined power generation system with CO2 recovery by oxygen combustion method

    International Nuclear Information System (INIS)

    The authors newly propose and investigate two types of carbon dioxide recovering SOFC/GT combined power generation systems in which a gas turbine with carbon dioxide recycle or water vapor injection is adopted as the bottoming cycle. In these systems, fuel gas is first introduced to a SOFC, and its exhaust fuel gas is afterburned by pure oxygen. Carbon dioxide or water vapor is also injected into the combustor to reduce the combustion gas temperature. The obtained combustion gas, which is composed of only carbon dioxide and water vapor, is introduced to a gas turbine in the bottoming cycle. The exhaust gas of the gas turbine preheats the injection gas, and then, carbon dioxide is separated by only cooling and water condensation. It is made clear that the overall efficiency of the system with carbon dioxide recycle reaches 63.87% (HHV) or 70.88% (LHV), and that of the system with water vapor injection reaches 65.00% (HHV) or 72.13% (LHV). These values are sufficiently high, indicating that the proposed systems are worth further research and development

  11. Increased generation of intracellular reactive oxygen species initiates selective cytotoxicity against the MCF-7 cell line resultant from redox active combination therapy using copper-thiosemicarbazone complexes.

    Science.gov (United States)

    Akladios, Fady N; Andrew, Scott D; Parkinson, Christopher J

    2016-06-01

    The combination of cytotoxic copper-thiosemicarbazone complexes with phenoxazines results in an up to 50-fold enhancement in the cytotoxic potential of the thiosemicarbazone against the MCF-7 human breast adenocarcinoma cell line over the effect attributable to drug additivity-allowing minimization of the more toxic copper-thiosemicarbazone component of the therapy. The combination of a benzophenoxazine with all classes of copper complex examined in this study proved more effective than combinations of the copper complexes with related isoelectronic azines. The combination approach results in rapid elevation of intracellular reactive oxygen levels followed by apoptotic cell death. Normal fibroblasts representative of non-cancerous cells (MRC-5) did not display a similar elevation of reactive oxygen levels when exposed to similar drug levels. The minimization of the copper-thiosemicarbazone component of the therapy results in an enhanced safety profile against normal fibroblasts. PMID:26951232

  12. Feasibilities of combination of hyperbaric oxygenation, ultraviolet blood irradiation, hemisorption in treating patients with sepsis as a complication of acute inflammatory diseases of abdomen

    International Nuclear Information System (INIS)

    Consideration is given to correlation of efficiency of results of treating patients with sepsis during traditional intensive therapy and during complex treatment, including hemosorption, hyperbaric oxygenation, ultraviolet blood irradiation, based on studying clinical picture, biochemical and immunological indices. Increase of treatment efficiency when using mentioned therapeutic measures, particularly their different combinations, is shown. 69 refs

  13. Combining benthic foraminiferal ecology and shell Mn/Ca to deconvolve past bottom water oxygenation and paleoproductivity

    NARCIS (Netherlands)

    Koho, K.A.; de Nooijer, L.J.; Reichart, G.J.

    2015-01-01

    The Mn/Ca of carbonate tests of living deep-sea foraminifera (Hoeglundina elegans, Bulimina aculeata, Uvigerina peregrina and Melonis barleeanus) were determined together with pore water manganese along a bottom water oxygen gradient across the lower boundary of the Arabian Sea oxygen minimum zone.

  14. Imbalance between oxygen photoreduction and antioxidant capacities in Symbiodinium cells exposed to combined heat and high light stress

    Science.gov (United States)

    Roberty, S.; Fransolet, D.; Cardol, P.; Plumier, J.-C.; Franck, F.

    2015-12-01

    During the last decades, coral reefs have been affected by several large-scale bleaching events, and such phenomena are expected to increase in frequency and severity in the future, thus compromising their survival. High sea surface temperature accompanied by high levels of solar irradiance has been found to be responsible for the induction of oxidative stress ultimately ending with the disruption of the symbiosis between cnidarians and Symbiodinium. For two decades, many studies have pointed to the water-water cycle (WWC) as being one of the primary mediators of this phenomenon, but the impacts of environmental stress on the O2 reduction by PSI and the associated reactive oxygen species (ROS)-detoxifying enzymes remain to be determined. In this study, we analyzed the impacts of acute thermal and light stress on the WWC in the model Symbiodinium strain A1. We observed that the high light treatment at 26 °C resulted in the up-regulation of superoxide dismutase, ascorbate peroxidase, and glutathione reductase activities and an increased production of ROS with no significant change in O2-dependent electron transport. Under high light and at 33 °C, O2-dependent electron transport was significantly increased relative to total electron transport. This increase was concomitant with a twofold increase in ROS generation compared with the treatment at 26 °C, while enzymes involved in the WWC were largely inactivated. These data show for the first time that combined heat and light stress inactivate antioxidant capacities of the WWC and suggests that its photoprotective functions are overwhelmed under these conditions. This study also indicates that cnidarians may be more prone to bleach if they harbor Symbiodinium cells having a highly active Mehler-type electron transport, unless they are able to quickly up-regulate their antioxidant capacities.

  15. Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation

    Science.gov (United States)

    Wang, Dongbo; Wang, Qilin; Laloo, Andrew; Xu, Yifeng; Bond, Philip L.; Yuan, Zhiguo

    2016-05-01

    Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4+ to NO3‑. Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5–3.0 to 0.3–0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater.

  16. Comparison of oral midazolam with a combination of oral midazolam and nitrous oxide-oxygen inhalation in the effectiveness of dental sedation for young children

    Directory of Open Access Journals (Sweden)

    Al-Zahrani A

    2009-03-01

    Full Text Available Aim: To compare the effectiveness of 0.6 mg/kg oral midazolam sedation alone and a combination of 0.6 mg/kg oral midazolam plus nitrous oxide-oxygen inhalation sedation, in controlling the behavior of uncooperative children during dental treatment. Study Design: The study had a crossover design where the same patient received two different sedation regimens, that is, oral midazolam 0.6 mg/kg and oral midazolam 0.6 mg/kg with nitrous oxide-oxygen inhalation during two dental treatment visits. Materials and Methods: Thirty children (17 males and 13 females were randomly selected for the study, with a mean age of 55.07 (± 9.29 months, ranging from 48 - 72 months. A scoring system suggested by Houpt et al. (1985 was utilized for assessment of the children′s behavior. Results : There was no significant (p > 0.05 difference in the overall behavior assessment between the two sedation regimens, that is, oral midazolam alone and oral midazolam plus nitrous oxide-oxygen. However, the combination of midazolam and nitrous oxide-oxygen showed significantly (p < 0.05 superior results as compared to midazolam alone, in terms of controlling movement and crying during local anesthesia administration and restorative procedures. Conclusion: Compared to oral midazolam alone, a combination of oral midazolam and nitrous oxide inhalation sedation appears to provide more comfort to pediatric dental patients and operators during critical stages of dental treatment.

  17. Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

    Science.gov (United States)

    Poff, A M; Ward, N; Seyfried, T N; Arnold, P; D'Agostino, D P

    2015-01-01

    The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT) and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control), low glucose (LG), ketone supplementation (βHB), hyperbaric oxygen (HBOT), or combination therapy (LG+βHB+HBOT) on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers. PMID:26061868

  18. Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

    Directory of Open Access Journals (Sweden)

    A M Poff

    Full Text Available The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control, low glucose (LG, ketone supplementation (βHB, hyperbaric oxygen (HBOT, or combination therapy (LG+βHB+HBOT on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.

  19. Combining Ventilatory Efficiency and Peak Oxygen Consumption in the Prognostic Assessment of Patients with Chronic Heart Failure

    OpenAIRE

    Toste, A; Soares, RM; Feliciano, J; Andreozzi, V; Silva, S.; Alves, S.; Ferreira, ML; Abreu, A.; Cruz Ferreira, R

    2010-01-01

    Cardiopulmonary exercise testing (CPET) is an objective method for assessment of functional capacity and for prognostic stratification of patients with chronic heart failure (CHF). In this study, we analyzed the prognostic value of a recently described CPET-derived parameter, the minute ventilation to carbon dioxide production slope normalized for peak oxygen consumption (VE/VCO2 slope/pVO2). METHODS: We prospectively studied 157 patients with stable CHF and dilated cardiomyopathy who per...

  20. The effects of vitamin E and C combination on hyperbaric oxygen-induced lung toxicity in rats

    OpenAIRE

    KIBRISLI, Erkan; Karaöz, Erdal; GÖKIRMAK, Münire; YAĞMURCA, Murat; IRMAK, M. Kemal

    2000-01-01

    Objectives: We examined the histopathological changes in the respiratory system of the rats induced by hyperbaric oxygen (HBO) administration and the effects of vitamin E and C on these alterations. Materials and Methods: Thirty adult rats were divided into three groups as control, HBO and HBO+Vit groups. Twenty animals in HBO and HBO+Vit groups were exposed to HBO on a daily basis for 45 days. Additionally, vitamin E and C were administered to the rats in the HB0+ Vit group intraperito...

  1. Clinical Observation on Acupuncture Combined with Hyperbaric Oxygenation in Treating Patients with Cervical Spondylosis of Nerve Root Type in Acute Phase

    Institute of Scientific and Technical Information of China (English)

    Wang Jian-xiong; Zhang Jun-feng

    2014-01-01

    Objective: To observe the therapeutic efficacy of acupuncture combined with hyperbaric oxygenation for cervical spondylosis of nerve root type in acute phase. Methods: One hundred cases with cervical spondylosis of nerve root type in acute phase were randomly divided into two groups, with 50 patients in each group. The patients in the treatment group were treated by acupuncture combined with hyperbaric oxygenation, and those in the control group only received the same acupuncture therapy as the treatment group. The therapeutic efficacy was evaluated after 2 courses of treatment. Results: In the treatment group, 27cases were cured, 9 cases showed markedly effective, and 4 cases were invalid, and the recovery rate was 67.5%, the total effective rate was 90.0%; in the control group, 18 cases were cured, 17 cases showed markedly effective, 15 cases were invalid, and the recovery rate was 36.0%, the total effective rate was 70.0%. There were statistically significant differences between two groupsin the recovery rate and the total effective rate (bothP Conclusion: Acupuncture combined with hyperbaric oxygenationhas rapid and reliable effects for cervical spondylosis of nerve root type in acute phase.

  2. Combined effect of oxygen deficient point defects and Ni doping in radio frequency magnetron sputtering deposited ZnO thin films

    International Nuclear Information System (INIS)

    Ni doped ZnO thin films with oxygen deficiency have been synthesized on glass substrates by radio frequency magnetron sputtering technique using argon plasma. The combined effect of point defects generated due to oxygen vacancies and Ni doping on the optical and electrical properties of ZnO thin films has been studied in this work. Ni doping concentrations were varied and the structural, optical and electrical properties of the films were studied as a function of doping concentrations. The films were characterized with X-ray diffractometer, UV–Vis–NIR spectrophotometer, X-ray photoelectron spectroscopy, atomic force microscopy and electrical conductivity measurements. Oxygen deficient point defects (Schottky defects) made the ZnO thin film highly conducting while incorporation of Ni dopant made it more functional regarding their electrical and optical properties. The films were found to have tunable electrical conductivity with Ni doping concentrations. - Highlights: • ZnO thin films prepared by radio frequency magnetron sputtering technique • Synthesis process was stimulated to introduce Schottky-type point defects. • Point defects and external doping of Ni made ZnO thin films more functional. • Point defect induced high electrical conductivity in ZnO thin film. • Significant shift in optical bandgap observed in ZnO with Ni doping concentrations

  3. Combination of On-line pH and Oxygen Transfer Rate Measurement in Shake Flasks by Fiber Optical Technique and Respiration Activity MOnitoring System (RAMOS

    Directory of Open Access Journals (Sweden)

    Jochen Büchs

    2007-12-01

    Full Text Available Shake flasks are commonly used for process development in biotechnologyindustry. For this purpose a lot of information is required from the growth conditions duringthe fermentation experiments. Therefore, Anderlei et al. developed the RAMOS technology[1, 2], which proviedes on-line oxygen and carbondioxide transfer rates in shake flasks.Besides oxygen consumption, the pH in the medium also plays an important role for thesuccessful cultivation of micro-organisms and for process development. For online pHmeasurement fiber optical methods based on fluorophores are available. Here a combinationof the on-line Oxygen Transfer Rate (OTR measurements in the RAMOS device with anon-line, fiber optical pH measurement is presented. To demonstrate the application of thecombined measurement techniques, Escherichia coli cultivations were performed and on-line pH measurements were compared with off-line samples. The combination of on-lineOTR and pH measurements gives a lot of information about the cultivation and, therefore, itis a powerful technique for monitoring shake flask experiments as well as for processdevelopment.

  4. Combined effect of oxygen deficient point defects and Ni doping in radio frequency magnetron sputtering deposited ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Saha, B., E-mail: biswajit.physics@gmail.com [Thin Film and Nano Science Laboratory, Department of Physics, Jadavpur University, 700 032 Kolkata (India); Department of Physics, National Institute of Technology Agartala, Jirania 799046, Tripura (India); Das, N.S.; Chattopadhyay, K.K. [Thin Film and Nano Science Laboratory, Department of Physics, Jadavpur University, 700 032 Kolkata (India)

    2014-07-01

    Ni doped ZnO thin films with oxygen deficiency have been synthesized on glass substrates by radio frequency magnetron sputtering technique using argon plasma. The combined effect of point defects generated due to oxygen vacancies and Ni doping on the optical and electrical properties of ZnO thin films has been studied in this work. Ni doping concentrations were varied and the structural, optical and electrical properties of the films were studied as a function of doping concentrations. The films were characterized with X-ray diffractometer, UV–Vis–NIR spectrophotometer, X-ray photoelectron spectroscopy, atomic force microscopy and electrical conductivity measurements. Oxygen deficient point defects (Schottky defects) made the ZnO thin film highly conducting while incorporation of Ni dopant made it more functional regarding their electrical and optical properties. The films were found to have tunable electrical conductivity with Ni doping concentrations. - Highlights: • ZnO thin films prepared by radio frequency magnetron sputtering technique • Synthesis process was stimulated to introduce Schottky-type point defects. • Point defects and external doping of Ni made ZnO thin films more functional. • Point defect induced high electrical conductivity in ZnO thin film. • Significant shift in optical bandgap observed in ZnO with Ni doping concentrations.

  5. Generation and scavenging of reactive oxygen species in wheat flag leaves under combined shading and waterlogging stress

    DEFF Research Database (Denmark)

    Li, Huawei; Cai, Jian; Liu, Fulai;

    2012-01-01

    peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase activity increased during 0–8 days after the onset of WS at 0–7, 8–15 and 16–23 DAA. At 16–24 DAA, Pn, the level of reactive oxygen species and activity of the antioxidative enzymes fully recovered in plants...... subjected to WS at 0–7 DAA, but only partially recovered under WS at 8–15 DAA. Expression of the photosythesis-responsive genes RcaB and Cab, and the antioxidative enzyme-related genes Mn-SOD, Cu/Zn-SOD, CAT and GR were consistent with the performance of Pn and the activity of the antioxidative enzymes....

  6. Gas turbine engine adapted for use in combination with an apparatus for separating a portion of oxygen from compressed air

    Science.gov (United States)

    Bland, Robert J.; Horazak, Dennis A.

    2012-03-06

    A gas turbine engine is provided comprising an outer shell, a compressor assembly, at least one combustor assembly, a turbine assembly and duct structure. The outer shell includes a compressor section, a combustor section, an intermediate section and a turbine section. The intermediate section includes at least one first opening and at least one second opening. The compressor assembly is located in the compressor section to define with the compressor section a compressor apparatus to compress air. The at least one combustor assembly is coupled to the combustor section to define with the combustor section a combustor apparatus. The turbine assembly is located in the turbine section to define with the turbine section a turbine apparatus. The duct structure is coupled to the intermediate section to receive at least a portion of the compressed air from the compressor apparatus through the at least one first opening in the intermediate section, pass the compressed air to an apparatus for separating a portion of oxygen from the compressed air to produced vitiated compressed air and return the vitiated compressed air to the intermediate section via the at least one second opening in the intermediate section.

  7. Combination of single walled carbon nanotubes/graphene oxide with paclitaxel: a reactive oxygen species mediated synergism for treatment of lung cancer

    Science.gov (United States)

    Arya, Neha; Arora, Aditya; Vasu, K. S.; Sood, A. K.; Katti, Dhirendra S.

    2013-03-01

    Heterogeneity in tumors has led to the development of combination therapies that enable enhanced cell death. Previously explored combination therapies mostly involved the use of bioactive molecules. In this work, we explored a non-conventional strategy of using carbon nanostructures (CNs) [single walled carbon nanotube (SWNT) and graphene oxide (GO)] for potentiating the efficacy of a bioactive molecule [paclitaxel (Tx)] for the treatment of lung cancer. The results demonstrated enhanced cell death following combination treatment of SWNT/GO and Tx indicating a synergistic effect. In addition, synergism was abrogated in the presence of an anti-oxidant, N-acetyl cysteine (NAC), and was therefore shown to be reactive oxygen species (ROS) dependent. It was further demonstrated using bromodeoxyuridine (BrdU) incorporation assay that treatment with CNs was associated with enhanced mitogen associated protein kinase (MAPK) activation that was ROS mediated. Hence, these results for the first time demonstrated the potential of SWNT/GO as co-therapeutic agents with Tx for the treatment of lung cancer.Heterogeneity in tumors has led to the development of combination therapies that enable enhanced cell death. Previously explored combination therapies mostly involved the use of bioactive molecules. In this work, we explored a non-conventional strategy of using carbon nanostructures (CNs) [single walled carbon nanotube (SWNT) and graphene oxide (GO)] for potentiating the efficacy of a bioactive molecule [paclitaxel (Tx)] for the treatment of lung cancer. The results demonstrated enhanced cell death following combination treatment of SWNT/GO and Tx indicating a synergistic effect. In addition, synergism was abrogated in the presence of an anti-oxidant, N-acetyl cysteine (NAC), and was therefore shown to be reactive oxygen species (ROS) dependent. It was further demonstrated using bromodeoxyuridine (BrdU) incorporation assay that treatment with CNs was associated with enhanced

  8. Combined oxygen, hydrogen, /sup 40/Ar//sup 39/Ar isotopic evaluation of molybdenite mineralization, east Pioneer Mountains, Montana

    Energy Technology Data Exchange (ETDEWEB)

    Chesley, J.T.; Snee, L.W.; O' Neil, J.R.

    1985-01-01

    The Pear Lake molybdenite (moly) prospect is in the Eastern Pioneer Wilderness Area, 30 km south of the Cannivan Gulch moly deposit. It lies on a NW-SE trend with other prospects that are contemporaneous. Mineralized veins outcrop sporadically over a 4 square mile area, with a major concentration in the center of the study area. Previous studies have suggested potential moly-mineralization at depth. /sup 40/Ar//sup 39/Ar age-spectra on hornblend (hb) from the granodiorite host rock indicate emplacement at 75.0 +/- 1 Ma, with biotite closure at 69.0 +/- .3 Ma, in the vicinity of Pear Lake. Hydrothermal muscovites from the moly-bearing veins have ages of 68.0 +/- .5 Ma. partial resetting of biotite cooling dates in the vicinity of mineralization are observed, but biotites on the outer portion of the mineralizing system are undisturbed. These relations suggest that mineralization occurred after the host pluton had cooled to below 280/sup 0/C. Quartz-magnetite isotopic temperatures are 380 to 420/sup 0/C for moly-veins. These data suggest that magmatic hydrothermal fluids operated in the upper portion of this molysystem. These isotopic data, combined with geologic mapping, suggest that the Pear Lake moly prospect resulted from a weak, short-lived magmatic hydrothermal event at depth, and is unlikely to contain economic levels of molybdenum. The combined /sup 40/Ar//sup 39/Ar-stable isotope approach should prove useful in evaluating other hydrothermal systems.

  9. Feasibility of actinide separation from UREX-like raffinates using a combination of sulfur- and oxygen-donor extractants

    International Nuclear Information System (INIS)

    A synergistic combination of bis(o-trifluoromethylphenyl)dithios-phosphinic acid and trioctylphosphine oxide has been recently shown to selectively remove uranium, neptunium, plutonium and americium from aqueous environment containing up to 0.5 M nitric acid and 5.5 g/l fission products. Here the feasibility of performing this complete actinide recovery from aqueous mixtures is forecasted for a new organic formulation containing sulfur donor extractant of modified structure based on Am(III) and Eu(III) extraction data. A mixture of bis(bis-m,m-trifluoromethyl)phenyl)-dithios-phosphinic acid and TOPO in toluene enhances the extraction performance, accomplishing Am/Eu differentiation in aqueous mixtures up to 1 M nitric acid. The new organic recipe is also less susceptible to oxidative damage resulting from radiolysis. (authors)

  10. Preparation of a high performance Pt-Co/C electrocatalyst for oxygen reduction in PEM fuel cell via a combined process of impregnation and seeding

    International Nuclear Information System (INIS)

    The preparation of a Pt-Co/C electrocatalyst for the oxygen reduction reaction in PEM fuel cells was achieved via a combined process of impregnation and seeding. The effects of initial pH of the precursor solution and Pt loading were all found to have a significant effect on both the electrocatalyst morphology and the cell performance when tested in a single PEM fuel cell. The optimum condition found for preparing the Pt-Co/C electrocatalyst was from an initial precursor solution pH of 2 at the metal loading of 23.6-30.3% (w/w). The Pt-Co/C electrocatalysts, formed under these optimal conditions, tested in a single PEM fuel cell with the carbon sub-layer, gave a cell performance of 772 mA/cm2 or 460 mW/cm2 at 0.6 V in a H2/O2 system. An electron pathway of oxygen reduction on the prepared Pt-Co/C electrocatalyst was also determined using a rotating disk electrode.

  11. Combined Increases in Mitochondrial Cooperation and Oxygen Photoreduction Compensate for Deficiency in Cyclic Electron Flow in Chlamydomonas reinhardtii[W][OPEN

    Science.gov (United States)

    Dang, Kieu-Van; Plet, Julie; Tolleter, Dimitri; Jokel, Martina; Cuiné, Stéphan; Carrier, Patrick; Auroy, Pascaline; Richaud, Pierre; Johnson, Xenie; Alric, Jean; Allahverdiyeva, Yagut; Peltier, Gilles

    2014-01-01

    During oxygenic photosynthesis, metabolic reactions of CO2 fixation require more ATP than is supplied by the linear electron flow operating from photosystem II to photosystem I (PSI). Different mechanisms, such as cyclic electron flow (CEF) around PSI, have been proposed to participate in reequilibrating the ATP/NADPH balance. To determine the contribution of CEF to microalgal biomass productivity, here, we studied photosynthesis and growth performances of a knockout Chlamydomonas reinhardtii mutant (pgrl1) deficient in PROTON GRADIENT REGULATION LIKE1 (PGRL1)–mediated CEF. Steady state biomass productivity of the pgrl1 mutant, measured in photobioreactors operated as turbidostats, was similar to its wild-type progenitor under a wide range of illumination and CO2 concentrations. Several changes were observed in pgrl1, including higher sensitivity of photosynthesis to mitochondrial inhibitors, increased light-dependent O2 uptake, and increased amounts of flavodiiron (FLV) proteins. We conclude that a combination of mitochondrial cooperation and oxygen photoreduction downstream of PSI (Mehler reactions) supplies extra ATP for photosynthesis in the pgrl1 mutant, resulting in normal biomass productivity under steady state conditions. The lower biomass productivity observed in the pgrl1 mutant in fluctuating light is attributed to an inability of compensation mechanisms to respond to a rapid increase in ATP demand. PMID:24989042

  12. Oxygen chemisorption cryogenic refrigerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1987-01-01

    The present invention relates to a chemisorption compressor cryogenic refrigerator which employs oxygen to provide cooling at 60 to 100 K. The invention includes dual vessels containing an oxygen absorbent material, alternately heated and cooled to provide a continuous flow of high pressure oxygen, multiple heat exchangers for precooling the oxygen, a Joule-Thomson expansion valve system for expanding the oxygen to partially liquefy it and a liquid oxygen pressure vessel. The primary novelty is that, while it was believed that once oxygen combined with an element or compound the reaction could not reverse to release gaseous oxygen, in this case oxygen will indeed react in a reversible fashion with certain materials and will do so at temperatures and pressures which make it practical for incorporation into a cryogenic refrigeration system.

  13. Oxygen Therapy

    Science.gov (United States)

    Oxygen therapy is a treatment that provides you with extra oxygen. Oxygen is a gas that your body needs to function. Normally, your lungs absorb oxygen from the air you breathe. But some conditions ...

  14. The combined effect of dissolved oxygen and nitrite on N2O production by ammonia oxidizing bacteria in an enriched nitrifying sludge.

    Science.gov (United States)

    Peng, Lai; Ni, Bing-Jie; Ye, Liu; Yuan, Zhiguo

    2015-04-15

    Both nitrite [Formula: see text] and dissolved oxygen (DO) play important roles in nitrous oxide (N2O) production by ammonia oxidizing bacteria (AOB). However, few studies focused on the combined effect of them on N2O production by AOB as well as the corresponding mechanisms. In this study, N2O production by an enriched nitrifying sludge, consisting of both AOB and nitrite-oxidizing bacteria (NOB), was investigated under various [Formula: see text] and DO concentrations. At each investigated DO level, both the biomass specific N2O production rate and the N2O emission factor (the ratio between N2O nitrogen emitted and the ammonium nitrogen converted) increased as [Formula: see text] concentration increased from 3 mg N/L to 50 mg N/L. However, at each investigated [Formula: see text] level, the maximum biomass specific N2O production rate occurred at DO of 0.85 mg O2/L, while the N2O emission factor decreased as DO increased from 0.35 to 3.5 mg O2/L. The analysis of the process data using a mathematical N2O model incorporating both the AOB denitrification and hydroxylamine (NH2OH) oxidation pathways indicated that the contribution of AOB denitrification pathway increased as [Formula: see text] concentration increased, but decreased as DO concentration increased, accompanied by a corresponding change in the contribution of NH2OH oxidation pathway to N2O production. The AOB denitrification pathway was predominant in most cases, with the NH2OH oxidation pathway making a comparable contribution only at high DO level (e.g. 3.5 mg O2/L). PMID:25644626

  15. Supplemental Oxygen

    Science.gov (United States)

    ... Disease Lookup > COPD > Diagnosing and Treating COPD Supplemental Oxygen Sometimes with chronic obstructive pulmonary disease (COPD), lung ... in people with severe lung disease Three Ways Oxygen Therapy Is Supplied Compressed oxygen gas and liquid ...

  16. Four-years experience with monitoring of persons at the treatment of children patients with neuroblastoma by 131I-MIBG combination with hyperbaric oxygen therapy

    International Nuclear Information System (INIS)

    Treatment of children patients with neuroblastoma by 131I-MIBG in combination with hyperbaric oxygen therapy (HBO) started in the Czech Republic in 1997. Estimation of radiation load from extemal irradiation plays very important role in the treatment scheme elaborated at the Department of Nuclear Medicine. According to this scheme, activities of 5.5 GBq and 3.7 GBq are administered at the first and repeated therapies,respectively. 3rd, 4th, 5th and 6th day after the administration patients undergo HBO in the Institute of Aviation Medicine Prague. Activity administration and following care are realised at the bed station of the Department of Nuclear Medicine, which is the workplace of III. category with unsealed radionuclide sources. Real dose equivalents were checked during the reported four-year period. Members of both groups were equipped by personal digital dosemeters STEPHEN 6000 for inspection. From the presented results, the following conclusions can be drawn: (1) Monitoring of family members has to be performed in spite of the fact that exceeding of equivalent dose of 5 mSv is non-realistic. Unexpected situation concerning behaviour of both parents and children cannot be excluded. Moreover, records of H-values have to be stored and analysed in the case of possible pregnancy. (2) A question arises in connection with the special limit 5 mSv: What is the whole time of the treatment? Is it possible to understand it, similarly as in the case of iodine therapy, as 5 mSv per year or is it necessary to take into account really the whole, often very long, time of the treatment? (3) Monitoring of the staff maintaining the hyperbaric chamber and ambulance drivers seems to be unnecessary. Under normal condition, the staff is outside the chamber and its contact with a patient is minimal. In unusual situation, the instructed nurse from the Department of Nuclear Medicine equipped by STEPHEN 6000 will estimate dose equivalent and contact responsible medical physicists. An

  17. Nitrogen transformations in the Arabian Sea Oxygen Minimum Zone as revealed by combined 15N-incubation experiments and functional gene expression analyses

    Science.gov (United States)

    Lam, P.; Jensen, M. M.; Lavik, G.; Kuypers, M. M. M.

    2009-04-01

    The Arabian Sea Oxygen Minimum Zone (OMZ) is considered to be one of the three major regions in the world's Ocean where nitrogen loss occurs in the water column. However, the exact pathway and the microbial players involved in the dinitrogen gas production, as well as the cycling of other inorganic nitrogen species, are not entirely clear. We performed incubation experiments with 15N-labeled substrates to investigate the vertical distribution of nitrogen-loss (denitrification and anammox) and other nitrogen transformations through the OMZ from the Omani shelf offshore towards the Indian coast. Intriguingly, there was no evidence of either anammox or denitrification in the northeastern Arabian Sea, which has generally been considered the main region of N-loss in the Arabian Sea. Instead, our results pointed to a substantial N-loss due to anammox from the Omani upwelling area. Moreover, a close coupling was demonstrated in the Omani shelf waters between anammox and DNRA (dissimilatory nitrate reduction to ammonium), with the latter process providing a substantial proportion of ammonium for the former. The co-occurrence of these processes was further confirmed by independent expression analyses of the functional gene biomarkers (anammox-type nirS, denitrifier-nirS and nrfA) for all these processes. Nitrification occurred particularly in the upper part of the OMZ and on the Omani shelf, predominantly mediated by crenarchaea over bacteria as shown by the expression of their respective ammonia monooxygenase genes (amoA). When detected, nitrification could supply at least 12% of the nitrite required by anammox. Meanwhile, nitrate reduction, traditionally regarded as the first step in denitrification, could be detected at higher rates than anammox and even at regions where dinitrogen gas production was not detected. This is consistent with the expression analyses of its biomarker gene (narG). In the northeastern Arabian Sea, our combined results suggested that there was

  18. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    Science.gov (United States)

    Wang, Xinmei; Cui, Dongmei; Zheng, Ling; Yang, Xiao; Yang, Hui

    2012-01-01

    Purpose To elucidate the different neuromechanisms of subjects with strabismic and anisometropic amblyopia compared with normal vision subjects using blood oxygen level–dependent functional magnetic resonance imaging (BOLD-fMRI) and pattern-reversal visual evoked potential (PR-VEP). Methods Fifty-three subjects, age range seven to 12 years, diagnosed with strabismic amblyopia (17 cases), anisometropic amblyopia (20 cases), and normal vision (16 cases), were examined using the BOLD-fMRI and PR-VEP of UTAS-E3000 techniques. Cortical activation by binocular viewing of reversal checkerboard patterns was examined in terms of the calcarine region of interest (ROI)-based and spatial frequency–dependent analysis. The correlation of cortical activation in fMRI and the P100 amplitude in VEP were analyzed using the SPSS 12.0 software package. Results In the BOLD-fMRI procedure, reduced areas and decreased activation levels were found in Brodmann area (BA) 17 and other extrastriate areas in subjects with amblyopia compared with the normal vision group. In general, the reduced areas mainly resided in the striate visual cortex in subjects with anisometropic amblyopia. In subjects with strabismic amblyopia, a more significant cortical impairment was found in bilateral BA 18 and BA 19 than that in subjects with anisometropic amblyopia. The activation by high-spatial-frequency stimuli was reduced in bilateral BA 18 and 19 as well as BA 17 in subjects with anisometropic amblyopia, whereas the activation was mainly reduced in BA 18 and BA 19 in subjects with strabismic amblyopia. These findings were further confirmed by the ROI-based analysis of BA 17. During spatial frequency–dependent VEP detection, subjects with anisometropic amblyopia had reduced sensitivity for high spatial frequency compared to subjects with strabismic amblyopia. The cortical activation in fMRI with the calcarine ROI-based analysis of BA 17 was significantly correlated with the P100 amplitude in VEP

  19. Combining Ruthenium(II) Complexes with Metal-Organic Frameworks to Realize Effective Two-Photon Absorption for Singlet Oxygen Generation.

    Science.gov (United States)

    Zhang, Wenxiang; Li, Bin; Ma, Heping; Zhang, Liming; Guan, Yunlong; Zhang, Yihe; Zhang, Xindan; Jing, Pengtao; Yue, Shumei

    2016-08-24

    Singlet oxygen ((1)O2), as a reactive oxygen species, has garnered serious attention in physical, chemical, and biological studies. In this paper, we designed and synthesized a new type of singlet-oxygen generation system by exchanging cationic ruthenium complexes (RCs) into anionic bio-MOF-1. The resulting bio-MOF-1&RCs can be used as effective photocatalysts for generation of singlet oxygen under both single-photon and two-photon excitation. Especially, the excellent two-photon absorption (TPA) behavior of bio-MOF-1&RCs aroused our interest greatly because their two-photon absorption band lies in the optical window of biological tissue. Here, we measured the ability of bio-MOF-1&RCs to generate (1)O2 by irradiation under both 490 and 800 nm wavelength light in DMF. 1,3-Diphenylisobenzofuran (DPBF) and 2',7'-dichlorofluorescein (DCFH) were used as typical (1)O2 traps to detect and evaluate the efficiency of generation of (1)O2 under single-photon and two-photon excitation, respectively. Results indicated that bio-MOF-1&[Ru(phen)3](2+) was able to effectively generate (1)O2 under both conditions. Our work creates a novel synergistic TPA system with the excellent photophysical properties of RCs and the unique microporous structure benefit of MOFs, which may open a new avenue for creation of a cancer treatment system with both photodynamic therapy and chemotherapy. PMID:27483010

  20. Using oxygen at home

    Science.gov (United States)

    Oxygen - home use; COPD - home oxygen; Chronic obstructive airways disease - home oxygen; Chronic obstructive lung disease - home oxygen; Chronic bronchitis - home oxygen; Emphysema - home oxygen; Chronic respiratory ...

  1. 高压氧加药物综合治疗突发性耳聋疗效分析%Therapeutic Effect of Hyperbaric Oxygen Combined with Medical Treatment on Sudden Deafness

    Institute of Scientific and Technical Information of China (English)

    黄红星; 杨立; 黄远; 唐梓轩; 赵之栋

    2011-01-01

    目的 探讨高压氧联合药物治疗突发性耳聋(sudden deafness,SD)的疗效.方法 2008年2月- 2010年7月,对174例SD患者采用高压氧(治疗压力0.2 MPa)及配合扩血管、营养神经等药物进行治疗,并观察其疗效.结果 高压氧联合药物治疗SD总有效率为85.7%,SD的发病就诊时间是影响预后的主要因素,发病就诊时间≤7d时,治疗有效率可达95.6%;≥15 d时,疗效明显降低.结论 高压氧联合药物治疗SD疗效确切,且高压氧治疗越早疗效越好.%Objective To observe the therapeutic effect of hyperbaric oxygen combined with medical treatment on sudden deafness. Methods Between February 2008 and July 2010, 174 patients with sudden deafness were treated by a combined therapy, including hyperbaric oxygen and medicals. The therapeutic effect was analyzed. Results The total effective rate was 85. 7%. The simultaneous phenomenon such as vertigo and vomiting and onset-diagnosis duration were the two major factors affecting the prognosis. When the onset-diagnosis duration was <[7 days, the effective rate reached 95. 6%; when the onset-diagnosis duration was≥15 days, the therapeutic effect decreased significantly. Conclusion Hyperbaric oxygen combined with medical treatment is effective for sudden deafness, and the hyperbaric oxygen treatment should be performed as earlier as possible.

  2. Oxygen analyzer

    Science.gov (United States)

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  3. Combination of blood oxygen level–dependent functional magnetic resonance imaging and visual evoked potential recordings for abnormal visual cortex in two types of amblyopia

    OpenAIRE

    Wang, Xinmei; Cui, Dongmei; Zheng, Ling; Yang, Xiao; Yang, Hui; Zeng, Junwen

    2012-01-01

    Purpose To elucidate the different neuromechanisms of subjects with strabismic and anisometropic amblyopia compared with normal vision subjects using blood oxygen level–dependent functional magnetic resonance imaging (BOLD-fMRI) and pattern-reversal visual evoked potential (PR-VEP). Methods Fifty-three subjects, age range seven to 12 years, diagnosed with strabismic amblyopia (17 cases), anisometropic amblyopia (20 cases), and normal vision (16 cases), were examined using the BOLD-fMRI and PR...

  4. Characterization of phosphorus species in sediments from the Arabian Sea oxygen minimum zone: Combining sequential extractions and X-ray spectroscopy

    OpenAIRE

    Kraal, Peter; Bostick, Benjamin C.; Behrends, Thilo; Reichart, Gert-Jan; Slomp, Caroline P.

    2015-01-01

    The bulk phosphorus (P) distribution in sediment samples from the oxygen minimum zone of the northern Arabian Sea was determined using two methods: sequential chemical extraction (the ‘SEDEX’ procedure) and X-ray absorption near-edge structure (XANES) spectroscopy of the phosphorus K-edge. Our results show good agreement between iron (Fe-)associated P and calcium phosphate minerals (Ca-P) determined by both methods. Furthermore, we find that SEDEX exchangeable P likely represents loosely Fe-b...

  5. Pre-treatment ferritin level and alveolar-arterial oxygen gradient can predict mortality rate due to acute/subacute interstitial pneumonia in dermatomyositis treated by cyclosporine a/glucocorticosteroid combination therapy: a case control study [corrected].

    Directory of Open Access Journals (Sweden)

    Kentaro Isoda

    Full Text Available BACKGROUND: Acute/subacute interstitial pneumonia in dermatomyositis (DM-A/SIP is a disease associated with a poor prognosis that resists treatment with glucocorticosteroids (GC and progresses rapidly in a period of weeks to months to death. We retrospectively studied outcomes, prognostic factors, and their relations with survival rate in patients with DM-A/SIP treated with early cyclosporine A (CSA/GC combination therapy and 2-hour postdose blood concentration monitoring. METHODS: This study comprised 32 DM-A/SIP patients who were simultaneously treated with CSA and prednisolone. Clinical and laboratory findings were compared between those who died due to DM-A/SIP and those surviving 24 weeks after beginning of therapy. Prognostic factors were extracted, and their relations with the survival rate were evaluated. RESULTS: Of the 32 DM-A/SIP patients, 25 survived, 5 died of DM-A/SIP, and 2 died of infections. In those who died due to DM-A/SIP, ferritin level and the alveolar-arterial oxygen gradient were significantly increased compared with the survivors (P<0.001 and P = 0.002, respectively. Multivariate analyses showed that ferritin and alveolar-arterial oxygen gradient were independent prognostic factors of poor outcome. The survival rate 24 weeks after beginning of treatment was significantly lower in those with a ferritin level of ≥ 600 ng/ml and alveolar-arterial oxygen gradient of ≥ 45 Torr (P<0.001 and P<0.001, respectively. All patients with both prognostic factors died, and the outcome was significantly poorer in these patients than in those with one or neither of the prognostic factors (P<0.001. CONCLUSIONS: We identified pre-treatment high serum ferritin level and high alveolar-arterial oxygen gradient as poor prognostic factors in DM-A/SIP patients undergoing early CSA/GC combination therapy and showed that the outcomes were poor in patients with both factors.

  6. Catalytic partial oxidation of coke oven gas to syngas in an oxygen permeation membrane reactor combined with NiO/MgO catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhibin; Ding, Weizhong; Zhang, Yunyan; Lu, Xionggang; Zhang, Yuwen; Shen, Peijun [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, No. 275 Mail box, 149 Yanchang Road, Shanghai 200072 (China)

    2010-06-15

    A high oxygen permeability and sufficient chemical and mechanical stability mixed ion and electron conductivity membrane to withstand the hash strong oxidation and reduction working conditions is significant for the membrane reactor to commercial-scale plant. In this paper, a disk-shaped Ba{sub 1.0}Co{sub 0.7}Fe{sub 0.2}Nb{sub 0.1}O{sub 3-{delta}} membrane was applied to a membrane reactor for the partial oxidation of methane in coke oven gas (COG) to syngas. The reaction was carried out using NiO/MgO solid solution catalyst by feeding COG. The reforming process was performed successfully; 95% CH{sub 4} conversion, 80% H{sub 2} selectivity, 106% CO selectivity and 16.3 ml cm{sup -2} min{sup -1} oxygen permeation flux were achieved at 1148 K. The reaction has been steadily carried out for more than 100 h. The NiO/MgO catalyst used in the membrane reactor exhibited good catalytic activity and resistance to coking in the COG atmosphere. Characterization of the membrane surface by SEM and XRD after long life test showed that both the surface exposed to the air side and reaction side still preserved the Perovskite structure which is implied that the practical application of this membrane as membrane reactor for partial oxidation of COG is promising. (author)

  7. Cerebral hemodynamic and oxygenation changes induced by inner and heard speech: a study combining functional near-infrared spectroscopy and capnography

    Science.gov (United States)

    Scholkmann, Felix; Klein, Sabine D.; Gerber, Ursina; Wolf, Martin; Wolf, Ursula

    2014-01-01

    The aim of this study was to investigate the effects of inner and heard speech on cerebral hemodynamics and oxygenation in the anterior prefrontal cortex (PFC) using functional near-infrared spectroscopy and to test whether potential effects were caused by alterations in the arterial carbon dioxide pressure (PaCO2). Twenty-nine healthy adult volunteers performed six different tasks of inner and heard speech according to a randomized crossover design. During the tasks, we generally found a decrease in PaCO (only for inner speech), tissue oxygen saturation (StO), oxyhemoglobin ([O2Hb]), total hemoglobin ([tHb]) concentration and an increase in deoxyhemoglobin concentration ([HHb]). Furthermore, we found significant relations between changes in [OHb], [HHb], [tHb], or StO and the participants' age, the baseline PETCO2, or certain speech tasks. We conclude that changes in breathing during the tasks led to lower PaCO (hypocapnia) for inner speech. During heard speech, no significant changes in PaCO occurred, but the decreases in StO, [OHb], and [tHb] suggest that changes in PaCO were also involved here. Different verse types (hexameter and alliteration) led to different changes in [tHb], implying different brain activations. In conclusion, StO, [OHb], [HHb], and [tHb] are affected by interplay of both PaCO reactivity and functional brain activity.

  8. The combination of hypoxia-response enhancers and an oxygen-dependent proteolytic motif enables real-time imaging of absolute HIF-1 activity in tumor xenografts

    International Nuclear Information System (INIS)

    The transcriptional activity of hypoxia-inducible factor-1 (HIF-1) is associated with tumor malignancies; therefore, it is important to comprehend its dynamism in solid tumors. However, a molecular imaging strategy to accurately access it remains to be developed. We constructed here a novel HIF-1-dependent reporter gene, 5HREp-ODD-luc, in which 5 copies of the hypoxia-response element (5HRE) enhance expression of the oxygen-dependent degradation (ODD) domain and luciferase (luc) fusion under hypoxia. Because the ODD domain caused the oxygen-dependent degradation of the ODD-Luc protein, the novel reporter gene showed little leak of luminescence under normoxia. Such a property caused an increase of the hypoxia-responsiveness up to about 4.7 x 104-fold. Moreover, the ODD domain caused rapid degradation of the ODD-Luc protein under normoxia, the luminescence reflected the dynamism of HIF-1 activity in real-time. The superiority of the novel reporter gene will surely accelerate analysis of the intratumoral HIF-1 activity during tumor progression and cancer treatments

  9. 电针配合高压氧治疗脑卒中偏瘫患者50例%Electro- acupuncture combined hyperbaric oxygen treating hemiplegia after stroke in 50 cases

    Institute of Scientific and Technical Information of China (English)

    张志刚; 孙毓

    2003-01-01

    BACKGROUND:Motor obstacle of limbs directly resulted from hemiplegia after stroke seriously affect patients′ daily work and living.Conventional medicine treatment can improve the function of hemiplegic limbs at some degree, but more and more studies confirm that conventional acupuncture therapy is an effective method to improve motor function of limbs.By point stimulating channel system, acupuncture therapy can regulate qi and smooth channel system, thus regulate whole body to achieve the goal of curing hemiplegia. Acupuncture combined with hyperbaric oxygen therapy can accelerate regeneration of cerebral cells, and promote the recovery of motor function of paralyzed limbs.

  10. Protection against Oxygen-Glucose Deprivation/Reperfusion Injury in Cortical Neurons by Combining Omega-3 Polyunsaturated Acid with Lyciumbarbarum Polysaccharide

    OpenAIRE

    Zhe Shi; Di Wu; Jian-Ping Yao; Xiaoli Yao; Zhijian (James) Huang; Peng Li; Jian-Bo Wan; Chengwei He; Huanxing Su

    2016-01-01

    Ischemic stroke, characterized by the disturbance of the blood supply to the brain, is a severe worldwide health threat with high mortality and morbidity. However, there is no effective pharmacotherapy for ischemic injury. Currently, combined treatment is highly recommended for this devastating injury. In the present study, we investigated neuroprotective effects of the combination of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and Lyciumbarbarum polysaccharide (LBP) on cortical neurons u...

  11. Combined oxygen- and carbon-isotope records through the Early Jurassic: multiple global events and two modes of carbon-cycle/temperature coupling

    DEFF Research Database (Denmark)

    Hesselbo, Stephen P.; Korte, Christoph

    2010-01-01

    The Jurassic comprises some 55 million years of Earth history. However, within the Jurassic, only one major environmental change (hyperthermal) event is really well known - the Early Toarcian Oceanic Anoxic Event (OAE) at ~183 Ma - and until very recently the extent to which the accompanying......, to the extent that meaningful comparisons between these events can begin to be made. Here we present new carbon and oxygen isotope data from mollusks (bivalves and belemnites) and brachiopods collected through the marine Early Jurassic succession of NE England, including the Sinemurian...... demonstrated that both long-term and short-term carbon-isotope shifts from the UK Early Jurassic represent global changes in carbon cycle balances. The Sinemurian-Pliensbachian boundary event is an event of global significance and shows several similarities to the Toarcian OAE (relative sea-level change...

  12. Curative effect observation on myogenic cream combined with oxygen in the treatment for bedsore%生肌膏配合吹氧治疗褥疮的疗效观察

    Institute of Scientific and Technical Information of China (English)

    黄少姬

    2012-01-01

    Objective To investigate the clinical effect of myogenic cream combined with oxygen in the treatment for bedsore.Methods 28 cases of bedsore patients,with 42 Ⅱ phase to Ⅳ phase of the bedsore,were cleaned wounds with 3% hydrogen peroxide solution,and 0.9% saline solution after admission to hospital.And then coated myogenic cream after oxygen treatment.Results In this group of 28 patients,among 42 ulcers,35 were cured,5 excellent,2 effective,no invalid,the cure rate was 83.3%,the total efficiency was 100%.Conclusion Myogenic cream combined with oxygen in treatment for bedsore has convergence and export synergism,can promote wound healing,and it is a good method in treatment for bedsore.%目的 探讨生肌膏配合吹氧治疗褥疮的临床效果.方法 选取28例褥疮患者,42处Ⅱ期至Ⅳ期的褥疮,人院后用3%双氧水溶液和0.9%生理盐水溶液清洗创面,吹氧后创面外涂生肌膏治疗.结果 本组28例患者,42处褥疮中,痊愈35处,显效5处,有效2处,无效0处,治愈率83.3%,总有效率100%.结论 生肌膏配合吹氧治疗褥疮具有生肌、敛口等协同作用,促进创面愈合,是治疗褥疮的好方法.

  13. Appreciating Oxygen

    Science.gov (United States)

    Weiss, Hilton M.

    2008-01-01

    Photosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that…

  14. Mitigation strategies of intergranular corrosion in systems of reactors of water boiling (BWR). Combined action of the chemistry of the hydrogen and the oxygen

    International Nuclear Information System (INIS)

    Inter-Granular Stress Corrosion cracking (IGSCC) in austenitic stainless steel and in austenitic nickel-based alloys has been the subject of many studies the aim of which was to resolve one of the main problems faced by BWR nuclear power plants since the 1960s. This corrosion phenomenon is the result of the combined action of three factors: sensitization of the material, high local stresses and an aggressive medium. This paper deals with these factors separately and analyzes the oxidative chemistry of BWR reactors (aggressivity of the medium) as one the main causes if IGSCC. (Author)

  15. Clinical Experience With Hyperbaric Oxygen Combined With Ginkge-dipyridamole infusion to Treat sudden Deaf ness%高压氧联合银杏达莫静滴治疗突发性耳聋临床体会

    Institute of Scientific and Technical Information of China (English)

    孟新宇; 刘明秋

    2012-01-01

      Objective Observation of Clinical effect hyperbaric oxygen combined with Ginkgo dipyridamole infusion in treatment of sudden deafness. Methods 60 cases of sudden deafness patients in experimental group and the control group, the experimental group used Ginkgo dipyridancole combined with hyperbaric oxygen treatment, the control group using conventional treatment, the curative effect was observed in the two groups. Results The experimental group in 30 cases of ear number, hearing recovery in 13 cases of ear number, effective in 7 cases, effective in 9 cases, 1 cases are invalid, the total efficiency of 96.67%;than in the control group, the total efficiency of 86.67%,is much higher, the experimental group tinnitus disappeared and relieve ear number of 28 cases, the total effective rate was 90%, was 55%higher than in the control group. Conclusion Ginkgo-dipyridamole combined with hyperbaric oxygen on the treatment of sudden deafness with obvious therapeutic effect, and can alleviate the symptoms of tinnitus, can be used in the clinical treatment of sudden deafness.%  目的 观察高压氧联合银杏达莫静滴治疗突发性耳聋的临床疗效.结论 选取60例突发性耳聋的患者实验组及对照组,实验组使用银杏达莫联合高压氧治疗,对照组使用常规治疗,观察两组的疗效.结果 实验组中30例耳数,听力痊愈的有13例耳数,显效7例,有效9例,无效1例,总有效率96.67%;比对照组总有效率86.67%要高得多,实验组耳鸣消失和减轻的耳数为28例,总有效率为90%,明显比对照组的55%的高得多.结论 银杏达莫联合高压氧对治疗突发性耳聋有显著的临床疗效,并能明显减轻耳鸣的症状,可用于临床突发性耳聋的治疗.

  16. 高压氧联合护理干预对产后抑郁症的影响%Effect of hyperbaric oxygen therapy combined with nursing intervention on the postpartum depression

    Institute of Scientific and Technical Information of China (English)

    卢丽艳

    2011-01-01

    目的:探讨高压氧联合护理干预对产后抑郁症(PPD)的影响.方法:将120例产后抑郁症产妇随机分为对照组和观察组各60例,对照组给予常规治疗及护理;观察组给予高压氧联合护理干预治疗,治疗6周后进行疗效及抑郁评分(HAMD)比较.结果:治疗后观察组总有效率为96.67%,HAMD评分为(7.05±2.12)分;对照组总有效率为93.33%,HAMD评分为(8.34±3.45)分,两组疗效及HAMD评分比较差异有统计学意义(P<0.05).结论:应用高压氧联合护理干预对产后抑郁症的治疗具有较好的效果,可以显著缓解抑郁症状,提高产妇的生活质量.%Objective: To investigate the effect of hyperbaric oxygen therapy combined with nursing intervention on the postpartum depression.Methods: 120 puerperant with postpartum depression were randomly divided into a control group and an observation group ( 60 puerperant for each group ).The puerperant in the control group received routine treatment and nursing care;the puerperant in the observation group received hyperbaric oxygen therapy combined with nursing intervention.The treatment efficacy and depression scores ( HAMD ) were compared after treatment for 6 weeks.Results: After treatment, the total effective rate was 96.67% and HAMD scores were 7.05 ± 2.12 points in the observation group and 93.33%, 8.34 ± 3.45 points in the control group, the differences between the two groups were statistically significant ( P < 0.05 ).Conclusion: Hyperbaric oxygen therapy combined with nursing intervention has better effects in the treatment of postpartum depression, it can significantly relieve the symptoms of depression and improve the quality of life of puerperant.

  17. Effect of hyperbaric oxygen treatment combined with drug therapy on sudden deafness%药物联合高压氧治疗突发性聋132例

    Institute of Scientific and Technical Information of China (English)

    李严; 雷玲; 李向晖; 马丽涛; 罗晓英

    2008-01-01

    目的 探讨药物联合高压氧治疗(hyperbaric oxygen treatment,HBOT)突发性聋的效果.方法 连续就诊的261例突发性聋患者随机分为药物治疗组(对照组)和HBOT结合药物治疗组(CHBOT),对照组采用常规药物治疗,HBOT组除上述药物治疗外,在舱内压力达0.20 MPa下,吸纯氧30 min 2次(中间吸空气10 min),1/d.在治疗后第30天或其间结束治疗的时间点按预定疗效指标评价.结果 与对照组相比,CHBOT 组听力显著改善(P<0.01);耳鸣显著减轻,有效率为 76.8%, 对照组为56.63%(P<0.01).在有眩晕的患者中,CHBOT组98.11% 的患者消失,而对照组仅 83.3%消失(P<0.05).CHBOT组疗程明显短于对照组(P<0.01).分析显示,无论采用何种治疗方法,入院前病程长、听力丧失(PTA>55 dB)明显以及伴随眩晕的患者预后差.结论 CHBOT治疗突发性聋的疗效明显优于单纯药物治疗.尽早启动HBOT结合药物治疗是提高突发性聋治愈率的重要途径.

  18. Effect of combination of oxygen, ozone and VSD in healing traumatic wound surface%氧、臭氧及负压封闭引流联合应用对创面的治疗作用

    Institute of Scientific and Technical Information of China (English)

    黄显凯; 王韬; 朱渝军

    2011-01-01

    目的 探讨联合应用负压封闭引流、局部氧疗及臭氧治疗对创伤创面的治疗作用.方法 选择2009年8月~2010年9月期间收治的50例胸腹壁、背部、四肢严重皮肤及软组织损伤病人,男性30例,女性20例;年龄16~58岁,平均35.8岁.平均创面面积124.5cm2.清创后30例采用氧、臭氧及负压封闭引流综合治疗(简称综合组):20例按常规方法换药(常规组).观察综合治疗和常规治疗对创伤性创面愈合的细菌及组织学变化影响.结果 综合组创面愈合时间及创面植皮时间均较常规组明显缩短(P<0 05);综合治疗组第5、7天创面细菌数显著低于常规组(P<0.01).光镜下观察综合治疗组肌纤维水肿程度较轻,炎性细胞浸润及血管扩张充血均较常规组轻.结论 联合应用负压封闭引流、局部氧疗及臭氧治疗可以优势互补,显著提高皮肤及软组织创面的治疗效果.%Objective To investigate the therapeutical effect of combination of oxygen, ozone and VSD on traumatic wound surface. Methods We studied fifty patients with severe skin and soft tissue injury in thoracic and abdominal wall,back and limbs,who admitted to our hospital from Aug. 2009 to Sep. 2010. There were 30 males and 20 females,aging from 16 to 58 ( average 35.8 ) years. The mean area of wound surface was 124.5cm2. Thirty patients(the combined therapy group) were debrided in common way and disposed by combined therapy of oxygen,ozone and VSD. While the other 20 patients ( the routine therapy ) were treated with the routine disposal. The effect of hemostasis and healing on wound surface was observed. Results The healing time and skin grafting time of the wound surface in the combined therapy group were all shortened apparently in contrast with the routine group (P <0. 05 ). The bacterial number of the wound surface in the combined therapy group in the 5th and 7th day ( P <0. 01) was remarkably less than the routine group. Under light

  19. Combined radiation-protective and radiation-sensitizing agents. II. Radiosensitivity of hypoxic or aerobic Chinese hamster fibroblasts in the presence of cysteamine and misonidazole: implications for the oxygen effect with Appendix on calculation of dose-modifying factors

    International Nuclear Information System (INIS)

    Experiments have been done to test whether a hypoxic cell radiosensitizing agent (misonidazole) can be combined with a radioprotecting agent (cysteamine) to equalize partially the radiation response of hypoxic and aerobic mammalian cells in tissue culture. The results indicate that cysteamine will protect against the radiosensitization of a hypoxic cell sensitizing drug (2.5 mM misonidazole) at much lower concentration than it will protect against the radiosensitization of oxygen (350 μM). Thus the addition of a radiation-protective drug tends to cancel the drug benefit of the radiosensitizer and therefore increases the differential response of hypoxic and aerobic cells rather than equalizing this response. The data suggest that even in situations where tumor tissue absorbs far less radioprotective drug than normal tissue (e.g., WR 2721), one might expect difficulties with the simultaneous administration of radiosensitizing and radioprotecting drugs

  20. Hyperbaric Oxygen Combined With Drug Treatment of Sudden Deafness%高压氧联合药物治疗突发性耳聋临床对比研究

    Institute of Scientific and Technical Information of China (English)

    王栋武

    2015-01-01

    目的:重点探索高压氧联合药物应用于治疗突发性耳聋的有效性。方法挑选的研究对象是86例突发性耳聋患者,将患者分成两组,采用不同的方法治疗。结果对照组的有效率仅仅达到74.42%,显著低于观察组的97.67%。对照组的满意度较低,仅可达到72.09%,显著低于观察组的97.67%。结论高压氧联合药物应用于治疗突发性耳聋的有效性较高,值得推荐。%Objective To explore the effectiveness of hyperbaric oxygen combined with the focus of drug used in the treatment of sudden deafness. Methods The subjects were selected 86 cases of sudden deafness patients, the patients were divided into two groups, using different methods of treatment. Results The response rate in the control group reached only 74.42 percent, signiifcantly lower than the 97.67%in the observation group. Lower satisfaction with the control group, only up to 72.09%, signiifcantly lower than the 97.67% in the observation group. Conclusion The high effectiveness of hyperbaric oxygen combined with drugs used in the treatment of sudden deafness, is recommended.

  1. 高压氧联合糖皮质激素治疗难治性突发性聋疗效观察%Therapeutic effects of hyperbaric oxygen combined with glucocorticoid on refractory idiopathic sudden deafness

    Institute of Scientific and Technical Information of China (English)

    杨晨; 张禹; 李航; 孟祥恩; 潘树义

    2014-01-01

    目的 观察高压氧(hyperbaric oxygen,HBO)联合糖皮质激素(glucocorticoid,GC)对难治性突发性聋临床疗效.方法 经患者知情同意,并经医院伦理委员会批准,根据患者是否使用GC治疗,将有完整临床资料的79例突发性聋患者分为HBO联合GC治疗组44例,单纯HBO组35例.另外,在我院同期耳鼻喉科收治的复诊就医的突发聋患者中,选取使用GC治疗但未进行HBO治疗患者32例,作为单纯GC组.通过分析治疗有效率、治愈率和听力改善率,对比联合治疗与单纯HBO治疗及单纯GC药物治疗的疗效差异.结果 HBO联合GC组患者的治疗有效率(59.52%)和听力改善率[(61.3±14.7)%]明显高于单纯HBO组[28.13%,(43.6±5.5)%]和单纯GC组[31.25%,(56.4±4.1)%].结论 对难治性突发性聋HBO联合GC较单纯HBO治疗或GC治疗效果更好.%Objective Observe the therapeutic effects of hyperbaric oxygen (HB0) combined with glucocorticoid (GC) on refractory idiopathic sudden deafness.Methods Forty-two patients with sudden deafness (refractory idiopathic sudden deafness),who failed to recover after over one month of onset,were admitted into our Center from 2010 to 2013 for treatment with HBO combined with GC (referred to as the combined treatment group).Another 2 groups of patients with refractory idiopathic sudden deafness (each consisting of 32 patients),who were admitted into either our Center or the Department of Otorhinolaryngology of the Navy General Hospital and treated with simple HBO or GC,were used as controls.Through analyses of effective rates,cure rates and improvement rates in hearing,differences in therapeutic effects were compared between the patient group treated with HB0 combined with GC and the 2 control groups.Results The effective rate (59.52%) and improvement rate [(61.3 ± 4.7)%] for the combined treatment group were obviously higher than those of the simple HBO group[28.13%,(43.6 ± 5.5)%] and the simple hormone group [31.25

  2. 高压氧配合药物治疗突发性耳聋作用观察%To observe the effect of hyperbaric oxygen combined with drugs in the treatment of sudden deafness

    Institute of Scientific and Technical Information of China (English)

    金峰松; 潘统快

    2015-01-01

    目的:分析在临床对于突发性耳聋患者实施治疗过程中高压氧配合药物的治疗效果。方法收集在我院进行治疗的40例突发性耳聋患者,将患者分为观察组以及对照组,各20例。对照组患者使用常规药物治疗,观察组患者使用高压氧配合药物治疗的方法进行治疗。结果两组患者均能够取得一定的治疗效果,但观察组患者的临床治疗有效率明显高于对照组患者的临床治疗有效率,差异显著。结论对于突发性耳聋患者实施治疗的过程中使用高压氧配合药物治疗的形式能够取得更好的治疗效果,在临床上值得推广应用。%Objective: To analyze the clinical implementation of drug for patients with sudden deafness treatment with hy-perbaric oxygen treatment process. Methods: Collected 40 cases of sudden deafness patients in our hospital, the patients were di-vided into observation group and control group, 20 cases in each. The control group was treated with routine drug treatment, the observation group were treated with hyperbaric oxygen therapy with drug treatment.Results: Two groups of patients were able to achieve a certain therapeutic effect, but the clinical observation of patients in the treatment group, the effective rate was signifi-cantly higher than the control group in the treatment of patients with clinical efficiency, significant difference.Conclusion:The implementation of the treatment process of patients with sudden deafness with hyperbaric oxygen combined with drug treatment can achieve better therapeutic effect, worthy of clinical application.

  3. 中西医药联合高压氧治疗突发性耳聋疗效观察%Clinic effect observation of traditional chinese medicine and western medicine combined hyperbaric oxygen in treatment of sudden hearing loss

    Institute of Scientific and Technical Information of China (English)

    张登科; 李正贤; 江文; 刘阳云; 冯秀荣

    2011-01-01

    Objective To explore the clinic effect of traditional Chinese medicine and western medicine combined hyperbaric oxygen in treatment of sudden hearing loss.Methods 120 patients with sudden deafness were randomly divided into 2 groups.60 cases of group A treated by traditional Chinese medicine ( including radix bupleuri, rhynchophylla, salviae miltiorrbizae, radix gentianae, radix puerariae, rhizoma gastrodiae, hemlock parsley, phelledendron, rhizoma aeori tatarinowii, angelica, cedonopsis, gentian, cork, prunella, cyperus rotundus, etc.) and 60 cases of group B treated by western medicine ( including low molecular weight dextran, prostaglandin E1, adenosine triphosphate, coenzyme A, dexamethasone and vitamin, etc.) combined hyperbaric oxygen.Among these patients, there were74 males and46 females, rangingin age from 34 to72 yearn.Results A, 15 cases cured, 19 cases markedly, 17 cases effective, 9 healed cases, the total effective rate is 85%.In group B, 13 cases cured, 14 cases markedly, 16 cases effective, 17 healed cases.The total effective rate is 71.66%.The results in group A were better than that in group B ( P < 0.05).Conclusion The results showed that sudden hearing loss with traditional Chinese medicine and western medicine combined hyperbaric oxygen treatment is better than single western medicine treatment.%目的 观察中西医药联合高压氧治疗突发性耳聋的临床效果.方法 突发性耳聋患者120例,男74例,女46例,年龄34~72岁.随机分为中西医组(A组)和西医组(B组)各60例.两组均使用低分子右旋糖酐,前列腺素E1,三磷酸腺苷,辅酶A,地塞米松,维生素等.A组同时加服中药(柴胡、钩藤、丹参、龙胆草、党参,石菖蒲、当归、天麻、川芎、黄柏、夏枯草、葛根、香附等).两组均辅以高压氧治疗.结果 A组痊愈15例,显效19例,有效17例,无效9例,临床总有效率为85%.B组痊愈13例,显效14例,有效16例,无效17例,临床总有效率为71.66%.

  4. Effects of Dermlin and Mepilex Border combined with oxygen therapy on bedsore%德莫林及美皮康联合氧疗对压疮的治疗效果

    Institute of Scientific and Technical Information of China (English)

    朱连荣; 黄英; 王晓媛; 翟冰; 李谦

    2011-01-01

    目的 探讨德莫林及美皮康联合氧疗对压疮的疗效。方法 将60例由于各种原因所致压疮的老年血液肿瘤病患者随机分成两组,观察组30例,采用德莫林及美皮康联合氧疗的方法治疗处理;对照组30例,采用定时红外线灯照射及常规外科方法处理。比较两组治疗后压疮的恢复情况。结果 观察组压疮的有效率为100%明显高于对照组60%,差异有统计学意义(x2 =17.78,P<0.01),两组患者Ⅰ期压疮的治愈时间以及换药次数比较,差异有统计学意义[(11.4±1.13)h比(3.9±1.13)h,(21.2±1.39)次比(2.8±0.71)分;t分别为3.403,3.411;P<0.01]。结论 德莫林及美皮康联合氧疗的方法对各种原因引起的压疮有良好的治疗效果。%Objective To evaluate the effects of Dermlin and Mepilex Border combined with oxygen therapy on bedsore. Methods 60 neoplastic hematologic disorder patients suffering from bedsores arising from various causes were randomly divided into observational group (n =30) and control group (n =30). The former group was treated by Dermlin and Mepilex Border combined with oxygen therapy, the latter one was treated by timing irradiation of infrared lamp and routine surgical methods. The recovery conditions of bedsores were observed. Results The effective rate of the observational group was significantly higher than those of the control group [( 100% vs 60% ) ;x2 =17.78 ,P <0. 01]. There were significant differences in healing time and times of dressing change between both groups [( 11.4 ± 1.13 ) h vs ( 3.9 ± 1.13 ) h, (21.2 ± 1.39) vs (2.8 ± 0. 71 ) ;t =3. 403,3.411;P < 0. 01]. Conclusions Dermlin and Mepilex Border combined with oxygen therapy has satisfactory effects on treating bedsores arising from various causes.

  5. Changes in brain function and anatomical structure following treatment of hyperbaric oxygen for visual pathway abnormalities In 16 cases Evaluation of functional magnetic resonance Imaging combined with diffusion tensor imaging

    Institute of Scientific and Technical Information of China (English)

    Ziqian Chen; Ping Ni; Hui Xiao; Jinhua Chen; Gennian Qian; Youqiang Ye; Shangwen Xu; Jinliang Wang; Xizhang Yang

    2008-01-01

    BACKGROUND:There is a growing research focus on the combination of blood oxygenation level dependent functional magnetic resonance imaging(BOLD-fMRI)and diffusion tensor imaging(DTI)to evaluate visual cortical function and structural changes in the cerebrum,as well as morphological changes to the white matter fiber tracks,after visual pathway lesions.However,the combined application of BOLD-fMRI and DTI in treating of visual pathway abnormalities still requires further studies. OBJECTIVE:To observe and evaluate the effects of hyperbaric oxygen on visual pathway abnormalities,and to evaluate the characteristics of cerebral function and anatomic structural changes by using BOLD-fMRI combined with DTI technique. DESIGN:Case contrast observation. SETTING:Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS:Sixteen patients(9 males and 7 females,15-77 years old)with lateral or bilateral visual disorder induced by visual pathway lesions were selected from the Department of Neurology,Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from January 2006 to May 2007.These patients comprised the lesion group.Measures of interventional therapy:hyperbaric oxygen of two normal atmospheres for three courses(10 d/course)and routine internal medicine treatment.In addition,12 healthy subjects of similar sex and age to the lesion group were regarded as the control group.The control group underwent routine ophthalmological and ocular fundus examinations; diagnostic results were normal. The experiment received confirmed consent from the local ethic committee,and all patients provided informed consent.METHODS:BOLD-fMRI and DTI manifestations in the lesion group were observed before and after hyperbaric oxygen intervention,and the results were compared with the control group.The subjects were positioned on their back,and BOLD-fMRI images were collected with the following GRE EPI sequence:TR= 2 000 ms,TE=40 ms,layer thickness=5 mm

  6. Combination hyperbaric oxygen and temozolomide therapy in c6 rat glioma model Terapia combinada de oxigênio hiperbárico e temozomida no modelo C6 de glioma em ratos

    Directory of Open Access Journals (Sweden)

    Yaşar Dagıstan

    2012-06-01

    Full Text Available PURPOSE: Temozolomide (TMZ has anti-tumor activity in patients with malignant glioma. Hyperbaric oxygen (HBO may enhance the efficacy of certain therapies that are limited because of the hypoxic tumor microenvironment. We examined the combined effects of TMZ-HBO in a rat glioma model. METHODS: After stereotactic injection of C6/LacZ rat glioma cells into the Wistar rats brain, the rats were randomly assigned to three treatment groups [group 1, control treatment; group 2, TMZ alone; group 3, a combination of TMZ and HBO]. Rats were sacrificed 18 days after treatment, and number of intra-/peri-tumoral vessels, microendothelial proliferations, immunohistochemistry and necrotic area were evaluated. RESULTS: Tumoral tissue was stained only sparsely with GFAP. Temozolomide treatment was significantly decreased in tumor tissue intratumoral vessel number / total tumor area level. The level of Ki67 was significantly decreased in the tumor tissue of the group 3. Additionally, the total necrotic area / total tumor volume (% was decreased significantly in tumor tissue of the group 3 rats compared to group1 and 2. CONCLUSION: The combination of hyperbaric oxygen with temozolomide produced an important reduction in glioma growth and effective approach to the treatment of glioblastoma.OBJETIVO: A temozolomida (TMZ tem atividade anti-tumoral em pacientes com glioma maligno. Oxigênio hiperbárico (HBO pode aumentar a eficácia de terapias que são limitadas devido a um microambiente do tumor hipóxico. Foram examinados os efeitos combinados de TMZ-HBO em um modelo de glioma em rato. MÉTODOS: Após a injeção estereotáxica de células de glioma de rato C6/LacZ no cérebro de ratos Wistar, os ratos foram distribuídos aleatoriamente em três grupos de tratamento: Grupo 1: tratamento de controle. Grupo 2: TMZ sozinho. Grupo 3: uma combinação de TMZ e HBO. Os ratos foram sacrificados 18 dias após o tratamento. Foram avaliados o número de vasos intra

  7. Monitoring oxygenation.

    Science.gov (United States)

    Severinghaus, John W

    2011-06-01

    Cyanosis was used for a century after dentists began pulling teeth under 100% N(2)O in 1844 because brief (2 min) severe hypoxia is harmless. Deaths came with curare and potent anesthetic respiratory arrest. Leland Clark's invention of a polarographic blood oxygen tension electrode (1954) was introduced for transcutaneous PO2 monitoring to adjust PEEP and CPAP PO2 to prevent premature infant blindness from excess O2 (1972). Oximetry for warning military aviators was tried after WW II but not used for routine monitoring until Takuo Aoyagi (1973) discovered an equation to measure SaO2 by the ratio of ratios of red and IR light transmitted through tissue as it changed with arterial pulses. Pulse oximetry (1982) depended on simultaneous technology improvements of light emitting red and IR diodes, tiny cheap solid state sensors and micro-chip computers. Continuous monitoring of airway anesthetic concentration and oxygen also became very common after 1980. Death from anesthesia fell 10 fold between 1985 and 2000 as pulse oximetry became universally used, but no proof of a causative relationship to pulse oximetry exists. It is now assumed that all anesthesiologist became much more aware of the dangers of prolonged hypoxia, perhaps by using the pulse oximeters. PMID:21717228

  8. Effect of moist healing therapy combined with hyperbaric oxygen in the treatment of diabetic foot ulcers%湿性愈合疗法联合高压氧治疗糖尿病足溃疡的效果

    Institute of Scientific and Technical Information of China (English)

    倪栋梅

    2013-01-01

    目的 探讨湿性愈合疗法联合高压氧治疗糖尿病足溃疡的应用.方法 通过在临床实践中以传统换药为基础,再使用湿性愈合疗法联合高压氧治疗糖尿病足溃疡,评价患者对该疗法的满意度、切口愈合率、愈合时间、换药次数,并与单独使用传统换药相比较,进行两者之间的差异分析.结果 实验组显效18例(85.7%),有效3例(14.3%),对照组显效10例(47.6%),有效6例(28.6%),无效5例(23.8%),两组比较差异有统计学意义(x2=5.68,P<0.05);愈合时间实验组需要(27.8±3.75)d,对照组需要(38.6±3.81)d,两组比较差异有统计学意义(t=9.2,P<0.05);换药次数实验组需要(15.6±3.45)次,对照组需要(24.8±3.62)次,两组比较差异有统计学意义(t=8.4,P<0.05);患者满意度实验组为95.4%优于对照组的68.9%,两组比较差异有统计学意义(t=5.15,P<0.05).结论 采用以传统换药为基础,再使用湿性愈合疗法联合高压氧治疗糖尿病足溃疡能明显提高创面愈合率,减少换药次数,减轻护士工作量,其结果可为合理应用该疗法促进糖尿病足溃疡愈合又可减少患者的痛苦提供临床依据.%Objective To investigate the clinical application of moist healing therapy combined with hyperbaric oxygen in the treatment of diabetic foot ulcers.Methods The diabetic foot ulcers were treated by moist healing therapy combined with hyperbaric oxygen based on the traditional dressing in the clinical practice in the experimental group,and the control group received the traditional dressing alone.The patient satisfaction,the rate of wound healing,the healing time and the dressing change times were evaluated and compared,and the differences were analyzed between the two groups.Results The obvious effective and effective rates of wound healing were respectively 85.7% (18 cases) and 14.3% (3 cases) in the experimental group,and 47.6% (10 cases),28.6% (6 cases) in the control group

  9. Integration of oxygen membranes for oxygen production in cement plants

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus;

    2015-01-01

    The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...... are examined. The economic figures of merit are compared with those from a standard cryogenic plant. Both oxygen enriched air and full oxy-fuel cases allow for an increase in clinker production, use of alternative fuels as well as on-site electricity production. In addition, the full oxy-fuel cases...... generate a concentrated CO2 source that can be used for enhanced oil recovery, in combination with biomass gasification and electrolysis for synthesis gas production, or possibly sequestered. The cases with oxygen enriched air provide very promising economic figures of merit with discounted payback periods...

  10. Efecto de la mezcla ozono/oxigeno combinado con levofloxacina en un modelo de sepsis peritoneal en rata (Efect of ozone/oxygen mixture combined with levofloxacin in a model of peritoneal sepsis induced in rats

    Directory of Open Access Journals (Sweden)

    DMV. Zullyt Zamora Rodríguez

    2007-09-01

    Full Text Available ResumenEl objetivo de este trabajo fue evaluar el efecto de la mezcla ozono/oxígeno combinado con antibiótico y aplicado terapéuticamente en un modelo de sepsis peritoneal en rata. El estudio fue realizado en ratas Wistar macho (200-250 g, los cuales fueron divididos aleatoriamente en cinco grupos: 1. inducción de la infección peritoneal, sin tratamiento alguno; 2. infectados y tratados con levofloxacina (25mg/kg; 3. infectados y tratados con la mezcla ozono/oxigeno por vía intraperitoneal, a la dosis de 1 mg/kg de peso; 4 y 5. infectados y tratados con Levofloxacina (25 mg/kg más la mezcla ozono/oxigeno i.p a 0,4 y 1 mg/kg, respectivamente. Se determinó el porciento de mortalidad de los animales mediante la observación diaria y también se registró el peso de los animales. Los resultados mostraron que los grupos de animales que recibieron tratamientos combinados de antibiótico y la mezcla ozono/oxígeno tuvieron un elevado porciento de sobrevivencia, siendo del 77 hasta el 100 % a las 120 h y entre el 66 y el 77 % a las 240 h. Sin embargo, en el grupo tratado con antibiótico fue de un 77% a las 120 h, pero ya a las 240 h el por ciento de sobrevivencia fue del 33 %. Este estudio demostró la efectividad de la combinación de la mezcla ozono/oxígeno con un antibiótico de última generación. Sin embargo, la aplicación sola de ozono de forma terapéutica, por vía intraperitoneal, en este modelo de sepsis no fue efectivo por lo cual se requiere evaluar otras dosis y vías de administración del ozono. AbstractThe aim of this research was to evaluate the effect of ozone / oxygen mixture (OOM combined with an antibiotic and applied therapeutically in a model of peritoneal sepsis induced by rat faecal material. The study was performed in male Wistar rats weighing 200-250 g. The animals were divided in five groups. The first one was the infected control with faecal material alone. The second was also infected and treated with

  11. Oxygen permeation modelling of perovskites

    OpenAIRE

    Hassel, van, E Edwin; Kawada, Tatsuya; Sakai, Natsuko; Yokokawa, Harumi; Dokiya, Masayuki; Bouwmeester, Henny J.M.

    1993-01-01

    A point defect model was used to describe the oxygen nonstoichiometry of the perovskites La0.75Sr0.25CrO3, La0.9Sr0.1FeO3, La0.9Sr0.1CoO3 and La0.8Sr0.2MnO3 as a function of the oxygen partial pressure. Form the oxygen vacancy concentration predicte by the point defect model, the ionic conductivity was calculated assuming a vacancy diffusion mechanism. The ionic conductivity was combined with the Wagner model for the oxidation of metals to yield an analytical expression for the oxygen permeat...

  12. Home Oxygen Therapy

    Science.gov (United States)

    ... Oxygen Therapy Font: Aerosol Delivery Oxygen Resources Immunizations Pollution Nutrition Exercise Coming Of Age Older Adults Allergy ... oxygen is so cold it can hurt your skin. Keep a fire extinguisher close by, and let ...

  13. Longitudial observation of dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging combined with diffusion tensor imaging

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Functional magnetic resonance imaging (fMRI) is initially used for visual cortex location.However, the application of fMRI in investigating the development of visual pathway lesions needs to be further observed.OBJECTIVE: This study is to longitudially observe the dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI) combined with diffusion tensor imaging (DTI), and to analyze the characteristics of brain function and structural recombination at convalescent period of lesions.DESIGN: Randomized controlled observation.SETTING: Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: Eight patients with unilateral or bilateral visual disorder caused by visual pathway lesions,who admitted to Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA from January to September 2006 were involved, and served as experimental subjects. The patients, 6 males and 2 females, were aged 16 - 67 years. They had visual disorder confirmed by clinical examination, i.e. visual pathway lesion, which was further diagnosed by MR or CT. Another 12 subjects generally matching to those patients of experimental group in gender, age and sight, who received health examination in synchronization were involved and served as controls. The subjects had no history of eye diseases. Their binocular visual acuity (or corrected visual acuity) was over 1.0. Both routine examination of ophthalmology and examination of fundus were normal. Informed consents of detected items were obtained from all the subjects.METHODS: Signa Excite HD 1.5T magnetic resonance imaging system with 16 passages (GE Company,USA) and coil with 8 passages were used; brain functional stimulus apparatus (SAV-8800. Meide Company) was used for showing experimental mission. At the early stage

  14. 高压氧综合治疗突发性耳聋的疗效评价%An Effective Appraisal of Hyperbaric Oxygen Combined with Drugs Therapy for Sudden Deafness

    Institute of Scientific and Technical Information of China (English)

    胡丽娜; 姚昭文; 杜玉琴

    2001-01-01

    Objective:To investigate the effect of hyperbaricoxygen(HBO)combined with drugs therapy for sudden deafness(SD).Methods:Twenty-six patients(31ears)with SD were exposed to HBO[pure oxygen breathing at 250 kPa(2.5ATA)absolute for 30min,twice,with a 10 min air breathing breath in the chamber,once a day],meanwhile they were also given commonly used drugs(energy mixture,injectio salvia miltiorrhiza Co, dextran 40,vitamin B group and corticoids)for(17.5±6.73)days.Thirty patients(33 ears)for comparison(non-HBO group)were treated only by the above-mentioned drug without HBO.Results:HBO group:7 ears were cured,6 ears markedly improved,10 ears improved;non-HBO group:5 ears were cured,4 ears markedly improved,7 ears improved.The overall effective rate in HBO group(72.4%)was higher than that in non-HBO group(48.5%)(χ2=4.438,P<0.025).Conclusion:The therapeutic effect of HBO combined with drugs for SD is significantly better than that of simple drug treatment without HBO.%目的:探讨高压氧联合药物治疗突发性耳聋(突聋)的疗效。方法:26例(31耳)突发性耳聋患者(HBO组)在250kPa(2.5ATA)压力下吸纯氧30min共2次,中间吸空气10min,每日1次,同时配合能量合剂、复方丹参液、低分子右旋糖酐、B族维生素、皮质激素等药物治疗,平均疗程(17.5±6.73)天。将本组疗效与单纯使用同类药物治疗的30例(33耳)突聋(非HBO组)进行比较。结果:HBO组痊愈7耳,显效6耳,有效10耳,总有效率72.4%;非HBO组痊愈5耳,显效4耳,有效7耳,总有效率48.5%,两组比较χ2=4.438,P<0.025。结论:HBO联合药物治疗突聋的效果明显优于单纯药物治疗。

  15. Analysis of curative effect of Ginaton combined with hyperbaric oxygen in the treatment of sudden deafness%金纳多联合高压氧治疗突发性聋的疗效分析

    Institute of Scientific and Technical Information of China (English)

    张姝; 李玲香

    2014-01-01

    Objective To analyze the curative effect of EGb761 combined with Hyperbaric Oxygen therapy on Sudden hearing loss and to explore relationship between some correlative influencing factors and the therapeutic effect. Methods summarize and analyze the clinical data of 150 Sudden hearing loss patients from Jan 2010 to Dec 2011 in a retrospective way and to evaluate the efficacy. Results 1. In the comparison group, the female、the middle-aged people、the mental work-ers、little movement persons、general tension persons、single ear unwell’person occupies the highest proportion.2. among the 150 patients, 49 cases is cured, 30 cases is markedly effective,27 cases ineffective and53 cases is failed, and the total effec-tive rate was 62.72%.3. Taking all factor into consideration in this study, puretone threshold , Accompanied by dizziness, the length of time between attack and reception of treatment in effect of sudden deafness are of statistical meaning(P0.05). Conclusion 1. Middle-aged people and younger one have higher risks of sudden deafness. The mental worker is the main group. The main factors are high pressure, tired and lower quality of sleep. 2. Patients with EGb761 combined with Hyperbaric Oxygen treatment on the hearing type of low-frequency steep drop will have a better curative effect. Patients with high-frequency hearing loss or complete deafness hearing curve type of ill have a bad curative effect. 3. The main factor influence the curative effect of sudden hearing loss are hearing type graphs and the length of time between attack and reception of treatment.%目的:分析金纳多联合高压氧治疗突发性聋的疗效,并探讨突发性聋的相关发病因素与疗效的关系。方法回顾性总结分析2010年1月至2011年12月在我院诊断并治疗的150例突发性聋患者的一般临床资料并进行疗效评估。结果1、150例患者发病构成比调查中:女性、中年人、脑力劳动者、很少运动者、一般紧张

  16. Assessment of the radiation burden of persons involved in the treatment of paediatric patients with neuroblastoma by means of 131I-MIBG in combination with hyperbaric oxygen therapy

    International Nuclear Information System (INIS)

    The dose equivalents to the parents, the drivers transporting the patients to oxygen therapy, and the hyperbaric chamber operating personnel were evaluated. The surface contamination of the oxygen chamber and masks and the contamination of the ambulances were also measured. The dose equivalents to the family members over the entire treatment period did not exceed 5 mSv. The dose equivalents received by the drivers and hyperbaric chamber personnel did not exceed the natural background level. No surface contamination was ever detected. It is recommended that the monitoring of the drivers and oxygen chamber personnel be dropped, whereas monitoring of the parents be continued in view of the high probability of repeated therapy. Surface contamination measurement is necessary because this risk can never be ruled out. Care of the patient during transport, as well as potential decontamination, could be the responsibility of a duly instructed and trained nurse

  17. Determination of chemical oxygen demand in heterogeneous solid or semisolid samples using a novel method combining solid dilutions as a preparation step followed by optimized closed reflux and colorimetric measurement

    OpenAIRE

    Noguerol Arias, Joan; Rodríguez-Abalde, Ángela; Romero, Eva; Flotats Ripoll, Xavier

    2012-01-01

    This paper reports the development of an innovative sample preparation method for the determination of the chemical oxygen demand (COD) in heterogeneous solid or semisolid samples, with high suspended solids and COD concentrations, using an optimized closed re flux colorimetric method.

  18. Artificial oxygen transport protein

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  19. HYPERBARIC OXYGENATION AND AEROBIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Irvine D. Prather

    2004-03-01

    Full Text Available The continuing desire to improve performance, particularly at the national and international levels, has led to the use of ergogenic aids. Ergogenic aids are defined as 'a procedure or agent that provides the athlete with a competitive edge beyond that obtained via normal training methods'. Random drug testing has been implemented in an effort to minimize an athlete's ability to gain an unfair advantage. However, other means of improving performance have been tried. Blood doping has been used to enhance endurance performance by improving oxygen delivery to working muscles. As oxygen is carried in combination with the hemoglobin, it seems logical that increasing the number of red blood cells (RBC's in the body would increase the oxygen carrying capacity to the tissues and result in improved performance. The first experiments of removing and then reinfusing blood showed a significant improvement in performance time

  20. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  1. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  2. Anemia and Oxygen Delivery.

    Science.gov (United States)

    Bliss, Stuart

    2015-09-01

    Clinical assessment of tissue oxygenation is challenging. Anemia reflects a decreased oxygen carrying capacity of the blood and its significance in the perioperative setting relates largely to the associated risk of insufficient oxygen delivery and cellular hypoxia. Until meaningful clinical measures of tissue oxygenation are available in veterinary practice, clinicians must rely on evaluation of a patient's hemodynamic and ventilatory performance, along with biochemical and hemogasometric measurements. Blood transfusion is used commonly for treatment of perioperative anemia, and may improve tissue oxygenation by normalizing the rheologic properties of blood and enhancing perfusion, independent of increases in oxygen carrying capacity. PMID:26033442

  3. Drug Therapy and Combined with Hyperbaric Oxygen in the Treatment of Acute Cerebral Infarction Clinical Analysis%单纯药物治疗与联合高压氧治疗急性脑梗死临床分析

    Institute of Scientific and Technical Information of China (English)

    杨淑琴; 张泽萍

    2013-01-01

      Objective:To study the effects of hyperbaric oxygen in the treatment of cerebral infarction and clinical analysis. Method:A retrospective study of our hospital from 2010 July to 2012 March,80 patients with acute cerebral infarction. Patients were randomly divided into 2 groups, 40 cases in the control group only received drug therapy,The treatment group of 40 cases in addition to drug treatment,also given the hyperbaric oxygen therapy. According to the“European Stroke Scale”(ESS)in the treatment group and the control group before and after treatment,and observe the clinical curative effect,score. Result:Drug and hyperbaric oxygen in the treatment of acute cerebral infarction clinical curative effect is better than simple drug use. Conclusion:Early hyperbaric oxygen treatment,In many ways to better improve brain ischemia,hypoxia,so as to achieve the purpose of treatment.%  目的:探讨高压氧治疗脑梗死的效果并进行临床分析。方法:回顾性研究笔者所在医院2010年4月-2012年11月急性脑梗死住院病例80例。随机分为两组,对照组40例,仅单纯药物治疗。治疗组40例,单纯药物治疗+高压氧治疗。根据“欧洲卒中量表”(ESS)对治疗组和对照组于治疗前、后,进行评分并观察疗效。结果:药物联合高压氧治疗急性脑梗死临床疗效优于单纯使用药物。结论:及早进行高压氧的治疗,并配合康复锻炼对减少梗死后的残疾、提高生活质量有极大的帮助。

  4. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.

    2014-01-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  5. Hyperbaric oxygen therapy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002375.htm Hyperbaric oxygen therapy To use the sharing features on this page, please enable JavaScript. Hyperbaric oxygen therapy uses a special pressure chamber to increase ...

  6. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  7. Combined Treatment With Peroxisome Proliferator-Activated Receptor (PPAR) Gamma Ligands and Gamma Radiation Induces Apoptosis by PPARγ-Independent Up-Regulation of Reactive Oxygen Species-Induced Deoxyribonucleic Acid Damage Signals in Non-Small Cell Lung Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Eun Jong; Im, Chang-Nim; Park, Seon Hwa [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Moon, Eun-Yi [Department of Bioscience and Biotechnology, Sejong University, Seoul (Korea, Republic of); Hong, Sung Hee, E-mail: gobrian@kcch.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2013-04-01

    Purpose: To investigate possible radiosensitizing activities of the well-known peroxisome proliferator-activated receptor (PPAR)γ ligand ciglitazone and novel PPARγ ligands CAY10415 and CAY10506 in non-small cell lung cancer (NSCLC) cells. Methods and Materials: Radiosensitivity was assessed using a clonogenic cell survival assay. To investigate the mechanism underlying PPARγ ligand-induced radiosensitization, the subdiploid cellular DNA fraction was analyzed by flow cytometry. Activation of the caspase pathway by combined PPARγ ligands and γ-radiation treatment was detected by immunoblot analysis. Reactive oxygen species (ROS) were measured using 2,7-dichlorodihydrofluorescein diacetate and flow cytometry. Results: The 3 PPARγ ligands induced cell death and ROS generation in a PPARγ-independent manner, enhanced γ-radiation–induced apoptosis and caspase-3–mediated poly (ADP-ribose) polymerase (PARP) cleavage in vitro. The combined PPARγ ligand/γ-radiation treatment triggered caspase-8 activation, and this initiator caspase played an important role in the combination-induced apoptosis. Peroxisome proliferator-activated receptor-γ ligands may enhance the γ-radiation-induced DNA damage response, possibly by increasing γ-H2AX expression. Moreover, the combination treatment significantly increased ROS generation, and the ROS scavenger N-acetylcysteine inhibited the combined treatment-induced ROS generation and apoptotic cell death. Conclusions: Taken together, these results indicated that the combined treatment of PPARγ ligands and γ-radiation synergistically induced DNA damage and apoptosis, which was regulated by ROS.

  8. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...... of continental growth and volcanic outgassing, as well as biogeochemical processing of elements within the oceans. The author will seek to explore constraints on the history of oxygenation and understand which processes have regulated oxygen through this eon....

  9. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  10. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Arthur J. Ragauskas

    2005-09-30

    yield and 4 cP in viscosity in comparison to high AA pulp for the oxygen delignification. This difference is also seen for high-kappa SW kraft pulps with an average improvement of {approx}3% in yield and 3 cP in viscosity for low AA high kappa number 50 pulp. Low AA hardwood kappa number 20 pulp had an average improvement of {approx}4% in yield and 6-12 cP in viscosity as compared to high AA pulp. Lower kraft cooking temperature (160 vs. 170 C) in combination with the medium AA provides a practical approach for integrating high kappa pulping of hardwoods (i.e., low rejects) with an advanced extended oxygen delignification stage. ECF pulp bleaching of low and high kappa kraft SW and HW pulps exhibit comparable optical and physical strength properties when bleached D(EPO)D.

  11. Meta-analysis of the clinical efficacy of treatment of sudden deafness using hyperbaric oxygen combined with drug in China%国内高压氧联合药物治疗突发性耳聋临床疗效的Meta分析

    Institute of Scientific and Technical Information of China (English)

    库薇; 刘业海; 吴静; 王强; 童步生; 段茂利

    2014-01-01

    Objective To evaluate the clinical efficacy of treatment of sudden deafness using hyperbaric oxygen com-bined with drug in recent years. Methods We searched nearly five years Chinese academic journals, Chinese digital library, VIP Information Resource System, Superstar Digital Library, Chinese Biomedical Literature Database, Wanfang database about hyperbaric oxygen therapy combined drug therapy of sudden deafness randomized controlled studies met the inclusion criteria for the evaluation of methodological literature from 2008 to 2012 , and RevMan5.1 software and the quality standards Meta-analysis of randomized controlled studies were included. Result 20 randomized controlled studies were analyzed, a to-tal of 2554 cases, of which 1,347 cases received hyperbaric oxygen therapy combined with drug treatment as treatment group, in contrast 1,207 cases received drug therapy alone was the control group. We found that the treatment group had a signifi-cant clinical effect than contrast group (P<0. 00001), and in addition ,the early use of hyperbaric oxygen therapy had better effect than the patients with hyperbaric oxygen of treatment at late stage (P<0. 00001). Conclusion The application of hyper-baric oxygen therapy combined with drug show better than drug therapy alone was, and the introduction of hyperbaric oxygen therapy,at earlier stage shows better results.%目的:评价近几年来国内高压氧联合药物综合疗法治疗突发性耳聋的临床疗效。方法检索2008~2012年近五年来中国学术期刊、中国数字图书馆、维普信息资源系统、超星数字图书馆、中国生物医学文献数据库、万方数据库中关于高压氧联合药物综合治疗突发性耳聋的随机对照研究,对符合纳入标准的文献进行方法学的评价,并用RevMan5.1软件对符合质量标准的随机对照研究进行Meta分析。结果纳入了20个随机对照研究,患者总数为2554例,其中有1347例接受高压氧联合药

  12. Study of Pulmicort combined with the analysis of oxygen nebulizer inhalation adjuvant therapy on infant pneumonia%探讨普米克令舒结合氧气雾化器吸入辅助治疗小儿肺炎的疗效分析

    Institute of Scientific and Technical Information of China (English)

    丁树新

    2015-01-01

    Objective: The Pulmicort Respules combined with oxygen nebulizer inhalation in adjuvant treatment of infan-tile pneumonia clinical curative effect were analyzed.Methods:Extraction in May 2013 to 2015 years 2 months in the hospital treatment of 140 cases of pneumonia were randomly divided into observation group and control group, 70 cases in each, which the observation group take Pulmicort Respules combined with oxygen nebulizer inhalation in the treatment, control group taken normal saline combined with oxygen nebulizer inhalation in the treatment, compared with two groups of clinical curative effect. Results: The total effective rate of the observation group was 58.57% significantly higher than that of the control group, the dif-ference was statistically significant (P<0.05).Conclusion:Pulmicort Respules combined with oxygen nebulizer inhalation in ad-juvant treatment of infantile pneumonia is safe and effective, it is worth in clinical application.%目的:针对普米克令舒结合氧气雾化器吸入辅助治疗小儿肺炎的临床疗效进行研究分析。方法抽取2013年5月至2015年2月在本院救治的140例肺炎患儿,随机分成观察组和对照组,各70例,其中观察组采取普米克令舒结合氧气雾化器吸入辅助治疗,对照组采取生理盐水结合氧气雾化器吸入辅助治疗,比较两组的临床治疗效果。结果观察组治疗总有效率为为87.13%明显高于对照组的58.57%,差异具有统计学意义(P<0.05)。结论普米克令舒结合氧气雾化器吸入辅助治疗小儿肺炎安全有效,值得在临床医学上的推广运用。

  13. 低频电刺激联合高压氧对脑梗死后吞咽障碍的疗效观察%Effects of Low-Frequency Electric Stimulation Combined with Hyperbaric Oxygen on Swallow-ing Disorder after Cerebral Infarction

    Institute of Scientific and Technical Information of China (English)

    吕铭新

    2015-01-01

    目的:观察低频电刺激联合高压氧对脑梗死后吞咽障碍的疗效。方法:选择首次发病的脑梗死伴有吞咽障碍的患者224例,随机分为常规训练组、电刺激组、高压氧组和联合组各56例。4组均行一般治疗和吞咽功能训练;同时,电刺激组给予低频电刺激治疗;高压氧组给予高压氧治疗;联合组给予低频电刺激和高压氧联合治疗。4组治疗前、后均采用洼田饮水试验、标准吞咽功能评价(SSA)量表和吞咽障碍特异性生存质量(SWAL-QOL)量表进行疗效评定。结果:治疗后4组吞咽障碍均有一定程度改善(均 P<0.05);治疗后,电刺激组、高压氧组和联合组有效率和 SWAL-QOL 评分高于常规训练组,SSA 评分低于常规训练组,且联合组较电刺激组、高压氧组更优(均 P<0.05);电刺激组与高压氧组治疗有效率、SSA 评分及 SWAL-QOL 评分差异无统计学意义(均 P>0.05)。结论:低频电刺激联合高压氧治疗脑梗死后吞咽障碍,可明显改善患者的吞咽功能。%Objective:To observe the effects of low-frequency electric stimulation combined with hyperbaric oxygen on swallowing disorder after cerebral infarction. Methods: Two hundred and twenty-four cases of cerebral infarction patients with swallowing disorder were recruited. According to the digital random list method, all patients were divided into regular training group, electrical stimulation group, hyperbaric oxygen group and combination group. All groups were given general treatment and swallowing function training was applied in regular training group; Patients in electrical stimulation group were implemented low-frequency electric stimulation; hyperbaric oxygen therapy was given in hyperbaric oxygen group; low-frequency electric stimulation combined with hyperbaric oxygen therapy was applied in combination group. The effects were evaluated by using Kubota drinking water test

  14. Brain Oxygenation Monitoring.

    Science.gov (United States)

    Kirkman, Matthew A; Smith, Martin

    2016-09-01

    A mismatch between cerebral oxygen supply and demand can lead to cerebral hypoxia/ischemia and deleterious outcomes. Cerebral oxygenation monitoring is an important aspect of multimodality neuromonitoring. It is increasingly deployed whenever intracranial pressure monitoring is indicated. Although there is a large body of evidence demonstrating an association between cerebral hypoxia/ischemia and poor outcomes, it remains to be determined whether restoring cerebral oxygenation leads to improved outcomes. Randomized prospective studies are required to address uncertainties about cerebral oxygenation monitoring and management. This article describes the different methods of monitoring cerebral oxygenation, their indications, evidence base, limitations, and future perspectives. PMID:27521197

  15. Effect of hyperbaric oxygen in the adjuvant treatment of patients with severe hand-foot-mouth disease combined with encephalitis%高压氧辅助治疗手足口病合并脑炎患儿60例疗效观察

    Institute of Scientific and Technical Information of China (English)

    赵秀英; 阙利双; 陈实; 冯小伟; 廖锋; 李玲; 向伟

    2013-01-01

    Objective To investigate the effect of hyperbaric oxygen in the adjuvant treatment of patients with severe hand-foot-mouth disease (HFMD) combined with encephalitis. Methods One hundred and twenty patients with severe HFMD combined with encephalitis in the People's Hospital of Hainan Province from June 2008 to December 2011 were divided into the Hyperbaric oxygen group and control group, with 60 patients in each group, The Hyperbaric oxygen group received conventional therapy plus hyperbaric oxygen treatment, while the control group received conventional therapy only. The clinical efficacy in the two groups were compared. Results The total effective rate in the Hyperbaric oxygen group was 96.6%, which was significantly higher than that of the control group (70.0%). The improvement rate of EEG in the Hyperbaric oxygen group was 55.2%, which was significantly higher than that of the control group (35.7%). The cure rate of brain MRI in the Hyperbaric oxygen group was 50.0%, significantly better than that of the control group (20.0%). 'The sequela incidence was 18.33%, which was significantly decreased compared with the control group (35.0%). The differences were all statistically significant (P<0.05). Conclusion Adjuvant hyperbaric oxygen treatment can improve the clinical effect and cure rate, reduce the incidence of sequel and the disability rale of patients with severe HFMD disease, which is worthy to be extended in clinical practice.%目的 探讨高压氧辅助治疗重症手足口病合并脑炎患儿的临床效果.方法 以2008 年6 月至2011 年12 月期间我院收治的120 例重症手足口病合并脑炎患儿为研究对象,随机分为高压氧组和对照组各60 例.对照组给予常规治疗,高压氧组在常规治疗的基础上加用高压氧辅助治疗,对疗效进行对比分析.结果 高压氧组总有效率为96.6%,明显高于对照组的70.0%;高压氧组脑电图好转率为55.2%,高于对照组的35.7%;高

  16. 42 CFR 414.226 - Oxygen and oxygen equipment.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Oxygen and oxygen equipment. 414.226 Section 414... Equipment and Prosthetic and Orthotic Devices § 414.226 Oxygen and oxygen equipment. (a) Payment rules—(1) Oxygen equipment. Payment for rental of oxygen equipment is made based on a monthly fee schedule...

  17. How Does Oxygen Therapy Work?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. How Does Oxygen Therapy Work? Oxygen therapy provides you with extra ... be delivered to your lungs in several ways. Oxygen Therapy Systems Oxygen is supplied in three forms: ...

  18. Modeling Oxygen Transport in the Human Placenta

    Science.gov (United States)

    Serov, Alexander; Filoche, Marcel; Salafia, Carolyn; Grebenkov, Denis

    Efficient functioning of the human placenta is crucial for the favorable pregnancy outcome. We construct a 3D model of oxygen transport in the placenta based on its histological cross-sections. The model accounts for both diffusion and convention of oxygen in the intervillous space and allows one to estimate oxygen uptake of a placentone. We demonstrate the existence of an optimal villi density maximizing the uptake and explain it as a trade-off between the incoming oxygen flow and the absorbing villous surface. Calculations performed for arbitrary shapes of fetal villi show that only two geometrical characteristics - villi density and the effective villi radius - are required to predict fetal oxygen uptake. Two combinations of physiological parameters that determine oxygen uptake are also identified: maximal oxygen inflow of a placentone and the Damköhler number. An automatic image analysis method is developed and applied to 22 healthy placental cross-sections demonstrating that villi density of a healthy human placenta lies within 10% of the optimal value, while overall geometry efficiency is rather low (around 30-40%). In a perspective, the model can constitute the base of a reliable tool of post partum oxygen exchange efficiency assessment in the human placenta. Also affiliated with Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA.

  19. Composite oxygen ion transport element

    Science.gov (United States)

    Chen, Jack C.; Besecker, Charles J.; Chen, Hancun; Robinson, Earil T.

    2007-06-12

    A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

  20. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  1. Integrated turbomachine oxygen plant

    Science.gov (United States)

    Anand, Ashok Kumar; DePuy, Richard Anthony; Muthaiah, Veerappan

    2014-06-17

    An integrated turbomachine oxygen plant includes a turbomachine and an air separation unit. One or more compressor pathways flow compressed air from a compressor through one or more of a combustor and a turbine expander to cool the combustor and/or the turbine expander. An air separation unit is operably connected to the one or more compressor pathways and is configured to separate the compressed air into oxygen and oxygen-depleted air. A method of air separation in an integrated turbomachine oxygen plant includes compressing a flow of air in a compressor of a turbomachine. The compressed flow of air is flowed through one or more of a combustor and a turbine expander of the turbomachine to cool the combustor and/or the turbine expander. The compressed flow of air is directed to an air separation unit and is separated into oxygen and oxygen-depleted air.

  2. 赛百纤溶酶联合高压氧治疗对脑梗死急性期凝血功能及预后的影响%Influence of plasminogen combined hyperbaric oxygen therapy on prognosis and coagulation in patients with acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    姚汉玲; 杨珺

    2011-01-01

    Objective To investigate the influence of plasminogen combined hyperbaric oxygen therapy on prognosis and coagulation in patients with acute cerebral infarction.Methods 86 patients with acute cerebral infarction were randomly divided into two groups, hyperbaric oxygen combined fibrinolytic therapy( HBD group, n= 40 cases ) and hyperbaric oxygen therapy ( non-HBO group, n =46 cases ) were given respectively.Indexes of two groups of patients with coagulation, neurological deficit score and overall efficacy were recorded and analyzed.Results After treatment, the total efficacy in hyperbaric oxygen group( 92.5% )was significantly higher than non-HBO group ( 73.9% ), the difference was statistically significant ( P < 0.05 ).compared with before treatment, PT, APTT prolonged, and TT shortened in the 2 groups after treatment.Fib levels decreased and neurological deficit scores were significantly lower, the differences between them were statistically significant( P < 0.05 ), the hyperbaric oxygen group were superior to the non-HBO group( P < 0.05 ).Conclusion Plasmin combined hyperbaric oxygen therapy is a effective and safe method on the coagulation of acute cerebral infarction, the neurological deficit score and overall effect were improved obviously.%目的 探讨纤溶酶联合高压氧治疗对脑梗死急性期凝血功能及预后的影响.方法 86例急性脑梗死患者随机分为2组,分别给予纤溶酶联合高压氧治疗(高压氧组,n=40)和非高压氧治疗(非高压氧组,n=46),分析2组患者的凝血功能、神经功能缺损评分及总体疗效.结果 治疗后高压氧组总有效率(92.5%)显著高于非高压氧组(73.9%),差异有统计学意义(P<0.05).2组治疗后与治疗前比较,PT、APTT延长,TT缩短,Fib含量下降,神经功能缺损评分降低,差异均有统计学意义(P<0.05),且高压氧组优于非高压氧组(P<0.05).结论 纤溶酶联合高压氧治疗对脑梗死急性期的凝血功能、神经功能缺损评

  3. Atomic Oxygen Effects

    Science.gov (United States)

    Miller, Sharon K. R.

    2014-01-01

    Atomic oxygen, which is the most predominant species in low Earth orbit, is highly reactive and can break chemical bonds on the surface of a wide variety of materials leading to volatilization or surface oxidation which can result in failure of spacecraft materials and components. This presentation will give an overview of how atomic oxygen reacts with spacecraft materials, results of space exposure testing of a variety of materials, and examples of failures caused by atomic oxygen.

  4. Sediment Oxygen Demand Kinetics

    OpenAIRE

    Olinde, Lindsay

    2007-01-01

    Hypolimnetic oxygen diffusers increase sediment oxygen demand (SOD) and, if not accounted for in design, can further exacerbate anoxic conditions. A study using extracted sediment cores, that included both field and laboratory experiments, was performed to investigate SOD kinetics in Carvinâ s Cove Reservoir, a eutrophic water supply reservoir for Roanoke, Virginia. A bubble-plume diffuser is used in Carvinâ s Cove to replenish oxygen consumed while the reservoir is thermally stratified. ...

  5. Measuring tissue oxygenation

    Science.gov (United States)

    Soyemi, Olusola O. (Inventor); Soller, Babs R. (Inventor); Yang, Ye (Inventor)

    2009-01-01

    Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

  6. Mars in situ propellants: Carbon monoxide and oxygen ignition experiments

    Science.gov (United States)

    Linne, Diane L.; Roncace, James; Groth, Mary F.

    1990-01-01

    Carbon monoxide and oxygen were tested in a standard spark-torch igniter to identify the ignition characteristics of this potential Mars in situ propellant combination. The ignition profiles were determined as functions of mixture ratio, amount of hydrogen added to the carbon monoxide, and oxygen inlet temperature. The experiments indicated that the carbon monoxide and oxygen combination must have small amounts of hydrogen present to initiate reaction. Once the reaction was started, the combustion continued without the presence of hydrogen. A mixture ratio range was identified where ignition occurred, and this range varied with the oxygen inlet temperature.

  7. Clinical efficacy and safety of human umbilical cord mesenchymal stem cell transplantation combined with hyperbaric oxygen therapy in the treatment of traumatic epilepsy%人脐带间充质干细胞移植联合高压氧治疗外伤性癫痫的临床研究

    Institute of Scientific and Technical Information of China (English)

    徐峰; 王钦玉

    2013-01-01

    Objective To explore the clinical efficacy and safety of human umbilical cord mesenchymal stem cell transplantation and hyperbaric oxygen in the treatment of traumatic epilepsy. Methods Forty-eight patients with traumatic epilepsy admitted in our hospital were selected as research objects. The patients were divided into two groups according to random number table. Patients in group A (n=24) were treated with human umbilical cord mesen chymal stem cell transplantation combined with hyperbaric oxygen therapy, while those in group B were treated with hyperbaric oxygen therapy. The clinical efficacy and safety were compared between the two groups. Results After treatment, the clinical efficacy was significantly higher in group A than group B (95.83% vs 33.33%, P<0.05), and the safety was significantly better in group A (P<0.05). Conclusion For treating traumatic epilepsy, human umbilical cord mesenchymal stem cell transplantation combined with hyperbaric oxygen therapy has high clinical efficacy and good safety, which is worthy to be extended in clinical practice.%目的 探讨人脐带间充质干细胞移植联合高压氧治疗外伤性癫痫的临床疗效和安全性.方法 选取我院收治的48例外伤性癫痫患者,应用随机数字表法分成联合治疗组和单一治疗组,每组各24例.联合治疗组采用人脐带间充质干细胞移植联合高压氧治疗方案,单一治疗组采用高压氧治疗方案.观察并分析两组患者的临床疗效及安全性.结果 两组患者经过不同的治疗方案治疗后,联合治疗组的疗效(95.83%)较单一治疗组疗效好(33.33%),安全性高,其差异具有统计学意义(P<0.05).结论 人脐带间充质干细胞移植联合高压氧治疗外伤性癫痫临床疗效较好,安全性高,值得临床推广应用.

  8. Highest Oxygen Bar

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The world’s highest altitude Lhalu Wetland in Tibet is rebounding from past environmental damage In Lhasa, where the oxygen content is just 60 percent of that of the plain area, a place known as the "natural oxygen bar"is highly prized by residents.

  9. Traveling with Portable Oxygen

    Science.gov (United States)

    ... that is right for you depends on your travel plans, your health requirements, and your personal preferences. Compressed Oxygen Compressed ... notice before your ight if you plan to travel with oxygen. For this ... to review procedures and complete all necessary paperwork required by ...

  10. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  11. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  12. Observation of Curative Effect on Nonorganic Insomnia Aged Patients with Combined Right Zopiclone and Hyperbaric Oxygen Therapy%药物联合高压氧治疗老年非器质性失眠症患者疗效观察

    Institute of Scientific and Technical Information of China (English)

    张文惠; 努苏来提·艾合买提

    2015-01-01

    目的:观察右佐匹克隆联合高压氧治疗对老年非器质性失眠症患者睡眠的改善作用。方法应用右佐匹克隆片与高压氧联合药物治疗对31例入组的老年非器质性睡眠障碍患者做疗效对比,药物组单用右佐匹克隆片治疗,联合治疗组运用右佐匹克隆片联合高压氧治疗。联合治疗组均完成两个高压氧疗程。结果药物组治疗前、治疗后10天、治疗后20天总睡眠时间分别为(2.01±0.76、1.94±0.82、0.89±0.57),睡眠质量分别为(2.32±0.65、2.01±0.59、1.67±0.69),睡眠效率分别为(1.67±0.83、1.47±0.93、0.93±0.72)。联合组治疗前、治疗后10天、治疗后20天睡眠时间分别为(1.98±0.56、1.03±0.74、0.48±0.32),睡眠质量分别为(2.45±0.76、1.73±0.37、1.24±0.58),睡眠效率分别为(1.71±0.63、0.85±0.38、0.26±0.41),两组间比较差异均有统计学意义(P<0.05)。结论右佐匹克隆片联合高压氧治疗能够帮助老年非器质性睡眠障碍失眠症患者改善睡眠质量。%Objective To observe the hyperbaric oxygen therapy on nonorganic sleep disorders in elderly patients. Methods the drug treatment with hyperbaric oxygen combined drug therapy of 31 cases in the group do efficacy in elderly patients with nonorganic sleep disorders, drug group of Eszopiclone therapy, combined treatment group use the Eszopiclone with hyperbaric oxygen therapy. Complete two hyperbaric oxygen treatment course for combined treatment group. Results The total sleep time, wake up delay time and number of nighttime awakening between two groups before and after treatment are significant difference (P<0.05). Conclusion hyperbaric oxygen treatment can help elderly nonorganic sleep disorder patients to improve sleep quality.

  13. Effects of hyperbaric oxygenation on hemodynamics and oxygen balance in tissues of miners with vibration pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Larin, Eh.N.; Samokhatko, E.V.; Dorogan' , N.A. (Institut Gigieny Truda i Profzabolevanii, Krivoi Rog (Ukraine))

    1992-08-01

    Studies antihypoxic and microcirculation-stimulating effects of hyperbaric oxygenation in patients suffering from vibration pathologies. Combined clinical and laboratory examinations were conducted on a group of 56 miners diagnosed with the first stage of vibration disease. Ages of the patients varied from 40 to 49 years and duration of work at vibratory type tools was over 15 years. Hyperbaric oxygenation therapy was performed for 40-50 minutes every day in an OKA-MT single-seat compression chamber at a pressure of 1.5-1.7 atm. Hyperbaric therapy was accompanied by treatment with vitamins, biogenic stimulators, ganglioplegics and spasmolytics. Detailed observational data are given. The following conclusions are presented: hyperbaric oxygenation produces a positive effect on oxygen balance in tissues and regional bloodstreams and increases physical endurance; further research for elaborating therapeutic conditions of hyperbaric oxygenation for patients suffering from accompanying diseases is justified. 7 refs.

  14. Clarification of the oxygen adsorption properties of YBaCo_4O_7 at high temperature by thermogravimetry

    Institute of Scientific and Technical Information of China (English)

    朱保峰; 郝好山; 张勇; 贾建峰; 胡行

    2010-01-01

    The oxygen adsorption/desorption properties of YBaCo4O7 at high temperature were investigated by thermogravimetry(TG) method,in which two types of oxygen adsorption were combined.The first type adsorbed oxygen at about 700 °C and released the adsorbed oxygen at 880 °C.After the first type oxygen desorption,even the temperature and oxygen flow were kept the same,a second type oxygen adsorption at about 880 °C occurred and the adsorbed oxygen were released at above 980 °C.The combination of these two types of...

  15. Oxygen therapy as an additional component of cytostatic treatment for recurrent cervical cancer

    OpenAIRE

    R. F. Savkova; L. E. Rotobelskaya; L. F. Yudina; M. A. Gerashchenko; A. S. Dzasokhov

    2012-01-01

    The data obtained by the authors suggest that the efficiency of standard cytostatic therapy for recurrent cervical cancer in combination with chemotherapy and oxygen therapy has increased and the tolerance of cytostatic treatment during oxygen therapy improved.

  16. Yttrium doped BSCF membranes for oxygen separation

    DEFF Research Database (Denmark)

    Haworth, P.; Smart, S.; Glasscock, Julie;

    2011-01-01

    BSCF (x = 0) membrane. This was attributed to the combined effect of the formation of a greater number of oxygen vacancies, together with improved ion mobility, associated with the beneficial yttrium substitution into the BSCF perovskite structure which stemmed from the crystal lattice expansion....

  17. Enhancing aspergiolide A production from a shear-sensitive and easy-foaming marine-derived filamentous fungus Aspergillus glaucus by oxygen carrier addition and impeller combination in a bioreactor.

    Science.gov (United States)

    Cai, Menghao; Zhou, Xiangshan; Lu, Jian; Fan, Weimin; Niu, Chuanpeng; Zhou, Jiushun; Sun, Xueqian; Kang, Li; Zhang, Yuanxing

    2011-02-01

    Production enhancement of a novel antitumor compound aspergiolide A from shear-sensitive and easy-foaming marine-derived fungus Aspergillus glaucus HB1-19 in a 5-l stirred bioreactor was investigated. Two types of impellers, i.e., six-flat-blade disc turbine impeller (DT) and three-sector-blade pitched blade turbine impeller (PB) were used in this work. In cultures with fermentation medium, the combination of upper PB and lower DT led to the maximum dry biomass (13.8 g/l) and aspergiolide A production (19.3 mg/l). However, two PBs brought the highest aspergiolide A yield coefficient (1.9 mg/g dry biomass) despite it produced the lowest dry biomass (5.3 g/l). By contrast, two DTs and the upper DT and lower PB showed insignificant results. Feeding 0.35% (v/v) n-dodecane in cultures with upper PB and lower DT further improved aspergiolide A production by 31.0%, i.e., 25.3 mg/l, which is also 322% higher than that in the ordinary cultures with two DTs. PMID:21074418

  18. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect the...... optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen at...... similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

  19. Living with Oxygen Therapy

    Science.gov (United States)

    ... transportation carrier (for example, the airline or bus company). If you need oxygen while traveling, plan in ... NEXT >> Updated: February 24, 2012 Twitter Facebook YouTube Google+ SITE INDEX ACCESSIBILITY PRIVACY STATEMENT FOIA OIG CONTACT ...

  20. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Lucian A. Lucia

    2005-11-15

    Project Objective: The objectives of this project are as follows: (1) Examine the physical and chemical characteristics of a partner mill pre- and post-oxygen delignified pulp and compare them to lab generated oxygen delignified pulps; (2) Apply the chemical selectivity enhancement system to the partner pre-oxygen delignified pulps under mill conditions (with and without any predetermined amounts of carryover) to determine how efficiently viscosity is preserved, how well selectivity is enhanced, if strength is improved, measure any yield differences and/or bleachability differences; and (3) Initiate a mill scale oxygen delignification run using the selectivity enhancement agent, collect the mill data, analyze it, and propose any future plans for implementation.

  1. Therapeutic effect of hyperbaric oxygen and swallowing training combined with acupuncture at Fengchi acu-point on dysphagia caused by pseudobulbar paralysis after stroke%高压氧、吞咽训练及针刺风池穴治疗脑卒中后假性延髓麻痹所致吞咽障碍的疗效观察

    Institute of Scientific and Technical Information of China (English)

    刘光健; 王云甫; 何国厚; 罗国君; 王俊华; 李厚成; 席刚明

    2009-01-01

    Objective To observe the clinical therapeutic effect of hyperbaric oxygen (HBO) therapy and swallowing training combined with Fengchi acupoint acupuncture on dysphagia caused by pseudobulbar paralysis after stroke. Methods Seventy-five patients were randomly divided into control group, HBO therapy group, swallow training group, acupuncture group and combined treatment group (n = 15). Patients in all groups were given cerebro-vascular disease routine treatment. In addition, the patients in HBO therapy group, swallowing training group and ac-upuncture group were given HBO therapy, swallowing training and Fengehi (GB20) acupoint acupuncture simultane-ously, respectively. The patients in combined treatment group were given HBO therapy combined with swallowing training and Fengchi acupoint acupuncture. Modified Kubota-Chiari's swallowing functional classification was used to assess swallowing function before and on the 3rd d,6th d,9th d, 12th d, 15th d, 18th d and 21st d after treatment. Results It was shown that the patients in all groups but the control group got significant improvement in swallowing after treatment, as demonstrated by the swallowing function scores (P acupuncture group > swal-low training group > HBO therapy group > control group(P 针刺组>吞咽训练组>高压氧组>对照组,组间差异均有统计学意义(P<0.05).结论 高压氧、吞咽功能训练及针刺风池穴联合治疗脑卒中后假性延髓麻痹所致吞咽障碍具有协同效应,可进一步提高临床疗效,促进患者吞咽功能恢复.

  2. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    la Cour, M; Kiilgaard, Jens Folke; Eysteinsson, T;

    2000-01-01

    To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide.......To investigate the influence of acute changes in intraocular pressure on the oxygen tension in the vicinity of the optic nerve head under control conditions and after intravenous administration of 500 mg of the carbonic anhydrase inhibitor dorzolamide....

  3. A model analysis of arterial oxygen desaturation during apnea in preterm infants.

    Directory of Open Access Journals (Sweden)

    Scott A Sands

    2009-12-01

    Full Text Available Rapid arterial O(2 desaturation during apnea in the preterm infant has obvious clinical implications but to date no adequate explanation for why it exists. Understanding the factors influencing the rate of arterial O(2 desaturation during apnea (Sa(O₂ is complicated by the non-linear O(2 dissociation curve, falling pulmonary O(2 uptake, and by the fact that O(2 desaturation is biphasic, exhibiting a rapid phase (stage 1 followed by a slower phase when severe desaturation develops (stage 2. Using a mathematical model incorporating pulmonary uptake dynamics, we found that elevated metabolic O(2 consumption accelerates Sa(O₂throughout the entire desaturation process. By contrast, the remaining factors have a restricted temporal influence: low pre-apneic alveolar P(O₂causes an early onset of desaturation, but thereafter has little impact; reduced lung volume, hemoglobin content or cardiac output, accelerates Sa(O₂during stage 1, and finally, total blood O(2 capacity (blood volume and hemoglobin content alone determines Sa(O₂during stage 2. Preterm infants with elevated metabolic rate, respiratory depression, low lung volume, impaired cardiac reserve, anemia, or hypovolemia, are at risk for rapid and profound apneic hypoxemia. Our insights provide a basic physiological framework that may guide clinical interpretation and design of interventions for preventing sudden apneic hypoxemia.

  4. 骨髓间充质干细胞移植联合高压氧治疗兔脊髓冲击伤%Therapeutic effects of bone marrow mesenchymal stem cells transplantation combined with hyperbaric oxygen on spinal cord blast injury

    Institute of Scientific and Technical Information of China (English)

    裴少保; 方健; 王海峰; 梅厚东; 张迪; 蒋传海

    2011-01-01

    目的 利用兔骨髓间充质干细胞联合高压氧治疗兔脊髓冲击伤,评价其治疗效果是否优于其两种治疗方法单独应用的效果.方法 建立T9-T10段大白兔脊髓冲击伤模型,通过Reuter、改良Tarlov评分和体感诱发电位选择脊髓损伤程度相同的48只大白兔,随机分为4组,每组12只.12 h后对各组分别作空白对照、高压氧治疗、骨髓间充质干细胞移植、两者联合治疗方面的干预.6周后行运动感觉功能评分、免疫荧光示踪、甲苯胺蓝染色、免疫组化染色(Bax、Bcl-2检测凋亡)等检测,比较各组指标的差异.结果 高压氧治疗组和骨髓间充质干细胞移植组的运动学评分及病理学指标均优于空白对照组,差异有统计学意义(P<0.05),两者联合治疗组的相关指标较其他治疗组效果明显,差异有统计学意义(P<0.05).结论 单独应用干细胞移植和高压氧治疗均能对脊髓冲击伤产生一定的修复作用,两种治疗措施联合能发挥协同作用,增强治疗效果.%Objective To therapy spinal cord injury by bone marrow mesenchymal stem cells and hyperbaric oxygen, to evaluate whether their combined treatment effect is better than their respective effect when used separately or not. Methods Established the models of T9-T10 spinal cord injuries, evaluated the extent of injuries by making kinematics score and somatosensory evoked potential score of each rabbit after 12 h , then 48 rabbits were randomly divided into four groups( n = 12 ) , which treated nothing, bone marrow mesenchymal stem cells transplantation , hyperbaric oxygen intervention,combined treatments .respectively. Six weeks later. evaluated with kinematics score,and immunofluorescence tracing method, toluidine blue stain, immunohistochemistry ( Bax, Bcl-2 detection of apoptosis ), and estimated the therapeutic efficacy of each group. Results After six weeks ,we found that the treatment of combined treatment on spinal cord injury was

  5. Enhanced Glow Discharge Production of Oxygen

    Science.gov (United States)

    Ash, Robert; Zhong, Shi

    1998-01-01

    Studies starting in late seventies have shown Mars atmosphere can be used as a feedstock for oxygen production using simple chemical processing systems during early phases of the Mars exploration program. This approach has been recognized as one of the most important in-situ resource utilization (ISRU) concepts for enabling future round trip Mars missions. It was determined a decade ago that separation of oxygen can be accomplished efficiently by permeation through a silver membrane at temperatures well below 1000 K. This process involves adsorption of atomic oxygen on the surface and its subsequent diffusion through a silver lattice via an oxygen concentration gradient. We have determined recently that glow discharge can be used to liberate atomic oxygen from Mars atmosphere and that the oxygen can be collected through a silver permeation membrane. Recently, we demonstrated a substantial increase in energy efficiency of the process by applying a radio frequency discharge in combination with a silver permeation membrane. The experiments were performed using pure carbon dioxide in the pressure range equal to Mars surface conditions. Energy efficiency was defined as the ratio of the energy required to dissociate a unit mass of oxygen from carbon dioxide to the (electrical) energy consumed by the overall system during the dissociation and collection process. The research effort, started at NASA Langley Research Center, continued with this project. Oxygen production apparatus, built and operated under the research grant NAG1-1140 was relocated to the Atomic Beams Laboratory at ODU in July 1996, being since then in fall operation.

  6. Oxygen mass transfer in fermentation of bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    R. Ríos

    2011-12-01

    Full Text Available The purpose of this work was to obtain a correlation based on literature, depicting the relationships betwen the physical oxygen transfer rate (OTR and microbial oxygen uptake rate (OUR in order to determine the conditions (mass transfer coefficient, resulting on diferents combinations of aereations and agitations rates, under which growth will not be limited by oxygen. This correlation was adapted to culture with B. thuringiensis in order to estimate what biomass concentration are feasible for the physical limits set by operations conditions before microbial activity becomes limited by oxygen.

  7. 不同种类有机酸及其配施对烤烟生长和叶片非酶促活性氧代谢的影响%Effect of different types of organic acids and their combined application on the growth and leaf non-enzymatic active oxygen metabolism of flue-cured tobacco

    Institute of Scientific and Technical Information of China (English)

    胡皓月; 许自成; 李志刚; 张蕊; 冉法芬; 王满

    2011-01-01

    The effects of different types of organic acids and their combined application on the growth and leaf non-enzymatic active oxygen metabolism of flue-cured tobacco were studied. The results showed that applying organic acids accelerated the plant height, the largest leaf length and width, the dry weight of steam and leaf, the dry weight of root to promote the growth of flue-cured tobacco, single application of oleic acid or malic acid, combined application of malic acid and oleic acid, or combined application of malic acid, oleic acid and humic acid had most obvious influence on it. Moreover, applying organic acids increased the content of ascorbic acid (ASA) and reduced glutathione ( GSH ), decreased the accumulation of superoxide radical ( O2- · ), which were beneficial for the balance of the leaf non-enzymatic active oxygen metabolism of tobacco.The results indicated that humic acid and oleic acid were most effective in single application of organic acids, the production rate of O2- · reduced by 35. 33% and 37. 08% than the control, the content of ASA increased by 28. 64% and 36. 03%,the content of GSH increased by 19. 75% and 15.24%; combined application of malic acid and humic acid , or combined application of malic acid and oleic acid were most effective in combined application of organic acids, the production rate of O2- · reduced by 31.00% and 29. 96% than the control, the content of ASA increased by 28. 31% and 34. 05%, the content of GSH increased by 13.87% and 10. 18%.%研究了不同种类有机酸及其组合对烤烟生长和非酶促活性氧代谢的影响.结果表明,施用有机酸有效提高了烤烟株高、最大叶长、最大叶宽、茎叶干重和根系干重,促进了烤烟的生长,其中以油酸、苹果酸、苹果酸+油酸配施、苹果酸+油酸+腐殖酸配施处理的效果较好.施用有机酸显著提高了抗氧化物质抗坏血酸(ASA)和还原性谷胱甘肽(GSH)的含量,减少了

  8. 自体血液回收联合控制性降压减少输血及对脑组织氧合和乳酸代谢的影响%Combined autologous transfusion with controlled hypotension to reduce blood transfusion and the influence on brain tissue oxygenation and lactate metabolism

    Institute of Scientific and Technical Information of China (English)

    侯南丽; 袁莉; 刘爱杰; 王世端; 武贞芝

    2014-01-01

    Objective To observe the effects of blood salvage and controlled hypotension which can reduce allogeneic blood transfusion on brain tissue oxygenation and lactic acid metabolism in patients with spinal surgery, and to determine the efficacy and safety of combination. Methods Sixty patients scheduled for spinal surgery with ASA grade I-Ⅱ levels in our hospital from December 2011 to May 2013 were randomly divided into two groups with 30 cases in each:Experimental Group (blood salvage combing controlled hypotension) or Control Group. General anesthesia was chosen in all patients. Blood samples were taken from the right jugular bulb and radial arterial simultaneously before surgery (T0), the end of surgery(T2) and 24 hours after surgery (T3) for blood gas analysis. Arterial oxygen partial pressure (PaO2), arterial oxygen saturation degree (SaO2), jugular bulb blood oxygen partial pressure (PjvO2), jugular bulb oxygen saturation (SjvO2), arterial and venous blood lactic acid (LacA, Lacjv) were recorded. Cerebral arterial oxygen content (CaO2), jugular bulb oxygen content (CjvO2), cerebral oxygen consumption C (ajv) O2 , cerebral oxygen uptake rate (CERO2) and difference in arterial and venous lactic acid content (ADVL) were calculated according to Fick formula. T1 is the stable point of intraoperative controlled hypotension. Patients' infusion volume,blood loss,autologous blood transfusion,allogeneic blood transfusion and the hemoglobin levels were recorded at each time point of these two groups. Results There was no significant difference in age, body weight, heart rate (HR), preoperative hemoglobin level (Hb) and preoperative coagulation index between two groups(P>0.05). Allogeneic blood transfusion volumes were significantly less in Experimental Group than those in Control Croup (P0.05). The CaO2, CjvO2 decreased significantly at the end of surgery(T2) and 24 hours after surgery (T3)compared with T0 (P0.05). Blood pressure was significantly lower in Control Group

  9. Visible light optical coherence tomography measure retinal oxygen metabolic response to systemic oxygenation (Conference Presentation)

    Science.gov (United States)

    Yi, Ji; Liu, Wenzhong; Chen, Siyu; Backman, Vadim; Sheibani, Nader; Sorenson, Christine M.; Fawzi, Amani A.; Linsenmeier, Robert A.; Zhang, Hao F.

    2016-03-01

    The lack of capability to quantify oxygen metabolism noninvasively impedes both fundamental investigation and clinical diagnosis of a wide spectrum of diseases including all the major blinding diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Using visible light optical coherence tomography (vis-OCT), we demonstrated accurate and robust measurement of retinal oxygen metabolic rate (rMRO2) noninvasively in rat eyes. The rMRO2 was calculated by concurrent measurement of blood flow and blood oxygen saturation (sO2). Blood flow was calculated by the principle of Doppler optical coherence tomography, where the phase shift between two closely spaced A-lines measures the axial velocity. The distinct optical absorption spectra of oxy- and deoxy-hemoglobin provided the contrast for sO2 measurement, combined with the spectroscopic analysis of vis-OCT signal within the blood vessels. We continuously monitored the regulatory response of oxygen consumption to a progressive hypoxic challenge. We found that both oxygen delivery, and rMRO2 increased from the highly regulated retinal circulation (RC) under hypoxia, by 0.28+/-0.08 μL/min (p<0.001), and 0.20+/-0.04 μL/min (p<0.001) per 100 mmHg systemic pO2 reduction, respectively. The increased oxygen extraction compensated for the deficient oxygen supply from the poorly regulated choroidal circulation (CC).

  10. A Bifunctional Electrocatalyst for Oxygen Evolution and Oxygen Reduction Reactions in Water

    Science.gov (United States)

    Faschinger, Felix; Chattopadhyay, Samir; Bhakta, Snehadri; Mondal, Biswajit; Elemans, Johannes A. A. W.; Müllegger, Stefan; Tebi, Stefano; Koch, Reinhold; Klappenberger, Florian; Paszkiewicz, Mateusz; Barth, Johannes V.; Rauls, Eva; Aldahhak, Hazem; Schmidt, Wolf Gero

    2016-01-01

    Abstract Oxygen reduction and water oxidation are two key processes in fuel cell applications. The oxidation of water to dioxygen is a 4 H+/4 e− process, while oxygen can be fully reduced to water by a 4 e−/4 H+ process or partially reduced by fewer electrons to reactive oxygen species such as H2O2 and O2 −. We demonstrate that a novel manganese corrole complex behaves as a bifunctional catalyst for both the electrocatalytic generation of dioxygen as well as the reduction of dioxygen in aqueous media. Furthermore, our combined kinetic, spectroscopic, and electrochemical study of manganese corroles adsorbed on different electrode materials (down to a submolecular level) reveals mechanistic details of the oxygen evolution and reduction processes.

  11. Oxygen Reduction on Platinum

    DEFF Research Database (Denmark)

    Nesselberger, Markus

    This thesis investigates the electro reduction of oxygen on platinum nanoparticles, which serve as catalyst in low temperature fuel cells. Kinetic studies on model catalysts as well as commercially used systems are presented in order to investigate the particle size effect, the particle proximity...... effect and anion adsorption on the performance of Pt based electrocatalysts. The anion adsorption is additionally studied by in situ electrochemical infrared spectroscopy during the oxygen reduction reaction (ORR). For this purpose an in situ FTIR setup in attenuated total refection (ATR) configuration...... influence of the ion adsorption strength, which is observed in the “particle size studies” on the oxygen reduction rate on Pt/C catalysts, is further investigated under similar reaction conditions by infrared spectroscopy. The designed in situ electrochemical ATR-FTIR setup features a high level of...

  12. Electrochemical oxygen meter

    International Nuclear Information System (INIS)

    An electrochemical (electrolytic cell) device is specified for measuring the concentration of oxygen in a liquid alkali metal (e.g. in the liquid sodium heat transfer loops of liquid metal cooled fast breeder reactors). The oxygen content is determined by measuring the e.m.f. generated between a reference electrode and the molten metal by the conduction of oxygen ions there between through a solid electrolyte. A salient feature of the invention is the use, for the reference electrode, of a uniform mixture of either Ga, In or Sn and its oxide, the mixture being liquid at the temperature of operation and in intimate contact with the solid electrolyte. Another salient feature of the invention is the use, for the solid electrolyte, of high purity thoria doped with yttria, the material being sintered and fired to a high temperature to obtain a density of 98 to 99% theoretical. (U.K.)

  13. 凯时注射液联合高压氧治疗突发性耳聋患者的疗效观察%Observation of curative effects of Kaishi injection combined with hyperbaric oxygen therapy in treatment of sudden deafness

    Institute of Scientific and Technical Information of China (English)

    王郁

    2016-01-01

    目的::观察凯时注射液联合高压氧治疗突发性耳聋患者的临床疗效。方法:以收治的80例突发性耳聋患者为研究对象,随机双盲法将其分为对照组和观察组,每组各40例。对照组患者采取常规治疗(即给予患者血管扩张剂、营养神经剂等);观察组患者在对照组基础上行凯时注射液联合高压氧治疗,比较两组患者治疗前后纯音听力水平。结果:观察组患者的治疗总有效率85.0%(34/40)高于对照组的65.0%(26/40),差异有统计学意义(P<0.05)。治疗后,观察组患者纯音测听气导为(29.1±2.0) dB明显低于对照组的(36.3±2.4) dB,差异有显著性(P<0.01)。结论:在常规治疗基础上,凯时注射液联合高压氧治疗突发性耳聋患者的疗效优于单纯常规治疗。%Objective:To observe clinical curative effects of Kaishi injection combined with hyperbaric oxygen therapy in treat-ment of sudden deafness. Methods:80 patients with sudden deafness were taken as the research objects and were divided into two groups by randomized double blind method with 40 cases in each group. The control group was treated with conventional therapy ( vaso-dilators and nerve nutrition agetns, etc. ) , while the experimental group with Kaishi injection combined with hyperbaric oxygen therapy based on the treatment of the control group. The pure tone hearing levels of the two groups before and after the treatment were com-pared. Results:The total effective rate of the experimental group was 85% (34/40), that of the control group was 65. 0% (26/40), and the difference was statistically significant (P<0. 05). The air conduction of pure tone audiometry of the experimental group after the treatment was (29. 1±2. 0) dB, compared with (36. 3±2. 4)dB of the control group, and the difference was statistically significant (P<0. 01). Conclusions:The curative effects of Kaishi injection combined with hyperbaric oxygen therapy based on the conventional

  14. 高压氧联合醒脑静注射液对小儿病毒性脑膜炎的疗效%The efficacy of hyperbaric oxygen combined with Xingnaojing injection in the treatment of viral meningitis in children

    Institute of Scientific and Technical Information of China (English)

    林传琼

    2015-01-01

    目的:探讨高压氧联合醒脑静注射液对小儿病毒性脑膜炎运动功能及智力发育的影响。方法:选取我院收治的小儿病毒性脑膜炎患儿68例,随机分为观察组和对照组各34例,观察组给予高压氧联合醒脑静注射液治疗,对照组仅给予醒脑静注射液治疗。比较两组患儿运动功能及智力发育的改善情况。结果:两组患者治疗后上肢、下肢 FMA评分较治疗前均有明显改善,且观察组优于对照组;两组患者5个功能区发育商均有改善,观察组精细动作、适应能力、语言和社交能力发育商明显高于对照组。差异均有统计学意义。结论:高压氧联合醒脑静注射液治疗小儿病毒性脑膜炎,可明显提高患儿的运动功能及智力发育,提高生活质量。%Objective: To investigate the efficacy of hyperbaric oxygen combined with Xingnaojing injection on the motor function and intelligence development of children with viral meningitis. Methods: Sixty-eight cases of children with viral meningitis in our hospital were randomly divided into an observation group and a control group with 34 cases each. Hyperbaric oxygen combined with Xingnaojing injection was given in the observation group while only Xingnaojing injection in the control group. The improvement of motor function and intelligence development were compared between two groups. Results: The FMA scores for upper and lower limbs in two groups were significantly improved after the treatment, and were much higher in the observation group than in the control group. The developmental quotient (DQ) of 5 function areas was all improved, however, DQ of fine motor, adaptive capacity, language and social skills was significantly higher in the observation group than in the control group. All the differences were statistically significant. Conclusion: Hyperbaric oxygen combined with Xingnaojing injection in the treatment of children with viral meningitis can

  15. Hyperbaric oxygen and radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, R. [Medical Univ. of Graz (Austria). Dept. of Radiation; Hamilton-Farrell, M.R. [Whipps Cross Hospital, Leytonstone, London (United Kingdom). Hyperbaric Unit; Kleij, A.J. van der [Academic Medical Center, Amsterdam (NL). Dept. of Surgery] [and others

    2005-02-01

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  16. Hyperbaric oxygen and radiotherapy

    International Nuclear Information System (INIS)

    Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

  17. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

    Hessel, Trine W; Hyttel-Sorensen, Simon; Greisen, Gorm

    2014-01-01

    AIM: To compare absolute values of regional cerebral tissue oxygenation (cStO2 ) during haemodynamic transition after birth and repeatability during steady state for two commercial near-infrared spectroscopy (NIRS) devices. METHODS: In a prospective observational study, the INVOS 5100C and FORE...... INVOS and FORE-SIGHT cStO2 estimates showed oxygenation-level-dependent difference during birth transition. The better repeatability of FORE-SIGHT could be due to the lower response to change in saturation....

  18. Oxygen ion conductors

    Directory of Open Access Journals (Sweden)

    Stephen J Skinner

    2003-03-01

    A very interesting subgroup of this class of materials are the oxides that display oxygen ion conductivity. As well as the intrinsic interest in these materials, there has been a continued drive for their development because of the promise of important technological devices such as the solid oxide fuel cell (SOFC, oxygen separation membranes, and membranes for the conversion of methane to syngas1. All of these devices offer the potential of enormous commercial and ecological benefits provided suitable high performance materials can be developed. In this article we will review the materials currently under development for application in such devices with particular reference to some of the newly discovered oxide ion conductors.

  19. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch;

    2005-01-01

    glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen...... through a mechanism of vasodilatation and lowering of the intraocular pressure. Carbonic anhydrase inhibition reduces the removal of CO2 from the tissue and the CO2 accumulation induces vasodilatation resulting in increased blood flow and improved oxygen supply. This effect is inhibited by the cyclo...

  20. The Appropriate Use of Oxygen

    OpenAIRE

    Lubin, Stan

    1988-01-01

    The scientific evidence for the efficacy of oxygen therapy in acute hypoxemia is limited. In chronic hypoxemia continuous oxygen therapy appears to decrease mortality. Current indications for oxygen treatment are PaO2 less than 60 in acute hypoxemia and less than 55 in chronic hypoxemia. Physical and physiological hazards of oxygen are reviewed. Three syndromes of pulmonary oxygen toxicity are described: tracheobronchitis, adult respiratory distress syndrome, and bronchopulmonary dysplasia.

  1. Retinal oxygen extraction in humans

    OpenAIRE

    René M. Werkmeister; Doreen Schmidl; Gerold Aschinger; Veronika Doblhoff-Dier; Stefan Palkovits; Magdalena Wirth; Gerhard Garhöfer; Linsenmeier, Robert A.; Rainer A. Leitgeb; Leopold Schmetterer

    2015-01-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal b...

  2. Functional Oxygen Sensitivity of Astrocytes

    OpenAIRE

    Angelova, P. R.; Kasymov, V.; I. Christie; Sheikhbahaei, S.; Turovsky, E.; Marina, N.; Korsak, A.; Zwicker, J; Teschemacher, A. G.; Ackland, G. L.; Funk, G. D.; Kasparov, S; Abramov, A.Y.; Gourine, A V

    2015-01-01

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2 ) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental...

  3. 高压氧联合布地奈德福莫特罗粉吸入剂治疗成人支气管哮喘的临床观察%Clinical observation of hyperbaric oxygen combined budesonide and formoterol fumarate powder for inhalation treatment of adult patients with bronchial asthma

    Institute of Scientific and Technical Information of China (English)

    任伟波; 许婷; 邓世忠; 涂彩坤; 陈永丽

    2015-01-01

    目的:探讨高压氧联合布地奈德福莫特罗粉吸入剂治疗成人支气管哮喘的临床疗效。方法分析我院2013年1月~2014年8月收治的60例支气管哮喘的患者临床资料,依据治疗方法不同进行临床随机分组,常规治疗组30例和联合治疗组30例。结果两组支气管哮喘患者治疗前动脉血气分析结果、肺功能无明显差异(P>0.05),联合治疗组治疗后动脉血气分析结果、肺功能均优于常规治疗组,联合治疗组发作频率和程度均优于常规治疗组,差异有统计学意义(P<0.05)。结论高压氧联合布地奈德福莫特罗粉吸入剂治疗成人支气管哮喘临床症状改善明显,预后良好,值得临床推广应用。%Objective To study the clinical effect of hyperbaric oxygen combined budesonide and formoterol fumarate powder for inhalation in the treatment of adult patients with bronchial asthma. Methods 60 adult patients with bronchial asthma who were treated in our hospital from January 2013 to August 2014, were analyzed as the clinical data, were randomly divided into two groups according to the different treatment methods, with 30 cases in routine treatment group and 30 cases in combined treatment group. Results The analysis results of arterial blood gas and pulmonary function before the treatment of adult patients with bronchial asthma between the two groups were no significant differences(P>0.05), while which after treatment in combined treatment group was better than which in routine treatment group(P < 0.05). The seizure frequency and degree in combined treatment group was better than which in routine treatment group, the difference was statically significant(P<0.05). Conclusion Hyperbaric oxygen combined budesonide and formoterol fumarate powder for inhalation in the treatment of adult patients with bronchial asthma has obviously improved the clinical effect, has favourable prognosis, is worthy of clinical popularization and

  4. Optic nerve oxygen tension

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Pedersen, D B; Eysteinsson, T;

    2004-01-01

    The authors have previously reported that carbonic anhydrase inhibitors such as acetazolamide and dorzolamide raise optic nerve oxygen tension (ONPO(2)) in pigs. The purpose of the present study was to investigate whether timolol, which belongs to another group of glaucoma drugs called beta...

  5. Calibration Of Oxygen Monitors

    Science.gov (United States)

    Zalenski, M. A.; Rowe, E. L.; Mcphee, J. R.

    1988-01-01

    Readings corrected for temperature, pressure, and humidity of air. Program for handheld computer developed to ensure accuracy of oxygen monitors in National Transonic Facility, where liquid nitrogen stored. Calibration values, determined daily, based on entries of data on barometric pressure, temperature, and relative humidity. Output provided directly in millivolts.

  6. Oxygenated Derivatives of Hydrocarbons

    Science.gov (United States)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  7. Superhydrophobic porous surfaces: dissolved oxygen sensing.

    Science.gov (United States)

    Gao, Yu; Chen, Tao; Yamamoto, Shunsuke; Miyashita, Tokuji; Mitsuishi, Masaya

    2015-02-18

    Porous polymer films are necessary for dissolved gas sensor applications that combine high sensitivity with selectivity. This report describes a greatly enhanced dissolved oxygen sensor system consisting of amphiphilic acrylamide-based polymers: poly(N-(1H, 1H-pentadecafluorooctyl)-methacrylamide) (pC7F15MAA) and poly(N-dodecylacrylamide-co-5- [4-(2-methacryloyloxyethoxy-carbonyl)phenyl]-10,15,20-triphenylporphinato platinum(II)) (p(DDA/PtTPP)). The nanoparticle formation capability ensures both superhydrophobicity with a water contact angle greater than 160° and gas permeability so that molecular oxygen enters the film from water. The film was prepared by casting a mixed solution of pC7F15MAA and p(DDA/PtTPP) with AK-225 and acetic acid onto a solid substrate. The film has a porous structure comprising nanoparticle assemblies with diameters of several hundred nanometers. The film shows exceptional performance as the oxygen sensitivity reaches 126: the intensity ratio at two oxygen concentrations (I0/I40) respectively corresponding to dissolved oxygen concentration 0 and 40 (mg L(-1)). Understanding and controlling porous nanostructures are expected to provide opportunities for making selective penetration/separation of molecules occurring at the superhydrophobic surface. PMID:25659178

  8. Ocean Ridges and Oxygen

    Science.gov (United States)

    Langmuir, C. H.

    2014-12-01

    The history of oxygen and the fluxes and feedbacks that lead to its evolution through time remain poorly constrained. It is not clear whether oxygen has had discrete steady state levels at different times in Earth's history, or whether oxygen evolution is more progressive, with trigger points that lead to discrete changes in markers such as mass independent sulfur isotopes. Whatever this history may have been, ocean ridges play an important and poorly recognized part in the overall mass balance of oxidants and reductants that contribute to electron mass balance and the oxygen budget. One example is the current steady state O2 in the atmosphere. The carbon isotope data suggest that the fraction of carbon has increased in the Phanerozoic, and CO2 outgassing followed by organic matter burial should continually supply more O2 to the surface reservoirs. Why is O2 not then increasing? A traditional answer to this question would relate to variations in the fraction of burial of organic matter, but this fraction appears to have been relatively high throughout the Phanerozoic. Furthermore, subduction of carbon in the 1/5 organic/carbonate proportions would contribute further to an increasingly oxidized surface. What is needed is a flux of oxidized material out of the system. One solution would be a modern oxidized flux to the mantle. The current outgassing flux of CO2 is ~3.4*1012 moles per year. If 20% of that becomes stored organic carbon, that is a flux of .68*1012 moles per year of reduced carbon. The current flux of oxidized iron in subducting ocean crust is ~2*1012 moles per year of O2 equivalents, based on the Fe3+/Fe2+ ratios in old ocean crust compared to fresh basalts at the ridge axis. This flux more than accounts for the incremental oxidizing power produced by modern life. It also suggests a possible feedback through oxygenation of the ocean. A reduced deep ocean would inhibit oxidation of ocean crust, in which case there would be no subduction flux of oxidized

  9. Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

    Science.gov (United States)

    Graf, John; Taylor, Dale; Martinez, James

    2014-01-01

    ]. Combined with a mechanical compressor, a Solid Electrolyte Oxygen Separator (SEOS) should be capable of producing ABO grade oxygen at pressures >2400 psia, on the space station. Feasibility tests using a SEOS integrated with a mechanical compressor identified an unexpected contaminant in the oxygen: water vapour was found in the oxygen product, sometimes at concentrations higher than 40 ppm (the ABO limit for water vapour is 7 ppm). If solid electrolyte membranes are really "infinitely selective" to oxygen as they are reported to be, where did the water come from? If water is getting into the oxygen, what other contaminants might get into the oxygen? Microscopic analyses of wafers, welds, and oxygen delivery tubes were performed in an attempt to find the source of the water vapour contamination. Hot and cold pressure decay tests were performed. Measurements of water vapour as a function of O2 delivery rate, O2 delivery pressure, and process air humidity levels were the most instructive in finding the source of water contamination (Fig 3). Water contamination was directly affected by oxygen delivery rate (doubling the oxygen production rate cut the water level in half). Water was affected by process air humidity levels and delivery pressure in a way that indicates the water was diffusing into the oxygen delivery system.

  10. 高压氧联合山莨菪碱治疗时间点选择对突发性耳聋疗效的影响%Effect of hyperbaric oxygen combined with anisodamine treatment time point selection on curative effect of sudden deafness

    Institute of Scientific and Technical Information of China (English)

    崔晓雯; 姜永珊

    2014-01-01

    目的:观察不同时间点高压氧联合山莨菪碱治疗突发性耳聋对疗效的影响。方法将166例采用高压氧治疗( HBO)的突发性耳聋患者,分为山莨菪碱组88例与对照组78例,两组均给予常规药物治疗,山莨菪碱组每日治疗前30 min肌注山莨菪碱,比较不同时间点治疗前后听力的变化。结果在发病1天内开始治疗,山莨菪碱组38例,显效率90.48%;对照组28例,显效率80.00%;两组均可收到较好疗效;发病1天~1周内开始治疗,山莨菪碱组26例,显效率76.47%;对照组16例,显效率51.61%;山莨菪碱组比对照组效果好,差异有显著性意义( P<0.05);发病2周后开始治疗,两组疗效均较差。结论高压氧联合山莨菪碱在有效时间点内治疗突发性耳聋,临床疗效肯定。%Objective To observe the effect of different time points of hyperbaric oxygen combined with anisodamine in the treatment of sudden deafness on curative effect .Methods A total of 166 patients with sudden deafness treated by hyperbaric oxygen ( HBO) were divided into anisodamine group of 88 cases and control group of 78 cases.The two groups were given routine drug treatment.In addition, the anisodamine group received intramuscular injection of anisodamine 30 minutes be-fore treatment.The changes of hearing before and after treatment were compared at different time points .Results Two groups had excellent curative effects when the treatment initiated within the first 24 hours.In anisodamine group of 38 ca-ses, the effective rate was 90.48%;in control group of 28 cases, the effective rate was 80%.Anisodamine group had bet-ter curative effects than control group within the first week , with significant difference (P<0.05).In anisodamine group of 26 cases, the effective rate was 76.47%;in control group of 16 cases, the effective rate was 51.61%.The outcome can not be improved in both groups if the treatment was

  11. 高压氧联合山莨菪碱治疗时间点选择对突发性耳聋疗效的影响%Effect of hyperbaric oxygen combined with anisodamine treatment time point selection on curative effect of sudden deafness

    Institute of Scientific and Technical Information of China (English)

    崔晓雯; 姜永珊

    2014-01-01

    Objective To observe the effect of different time points of hyperbaric oxygen combined with anisodamine in the treatment of sudden deafness on curative effect .Methods A total of 166 patients with sudden deafness treated by hyperbaric oxygen ( HBO) were divided into anisodamine group of 88 cases and control group of 78 cases.The two groups were given routine drug treatment.In addition, the anisodamine group received intramuscular injection of anisodamine 30 minutes be-fore treatment.The changes of hearing before and after treatment were compared at different time points .Results Two groups had excellent curative effects when the treatment initiated within the first 24 hours.In anisodamine group of 38 ca-ses, the effective rate was 90.48%;in control group of 28 cases, the effective rate was 80%.Anisodamine group had bet-ter curative effects than control group within the first week , with significant difference (P<0.05).In anisodamine group of 26 cases, the effective rate was 76.47%;in control group of 16 cases, the effective rate was 51.61%.The outcome can not be improved in both groups if the treatment was initiated after 2 weeks.Conclusion Hyperbaric oxygen combined with anisodamine in the treatment of sudden deafness within the effective time has clinical curative effect affirmation .%目的:观察不同时间点高压氧联合山莨菪碱治疗突发性耳聋对疗效的影响。方法将166例采用高压氧治疗( HBO)的突发性耳聋患者,分为山莨菪碱组88例与对照组78例,两组均给予常规药物治疗,山莨菪碱组每日治疗前30 min肌注山莨菪碱,比较不同时间点治疗前后听力的变化。结果在发病1天内开始治疗,山莨菪碱组38例,显效率90.48%;对照组28例,显效率80.00%;两组均可收到较好疗效;发病1天~1周内开始治疗,山莨菪碱组26例,显效率76.47%;对照组16例,显效率51.61%;山莨菪碱组比对照组效果好

  12. Oxygen Isotopic and Petrological Constraints on the Origin and Relationship of IIE Iron Meteorites and H Chondrites

    Science.gov (United States)

    McDermott, K. H.; Greenwood, R. C.; Franchi, I. A.; Anand, M.; Scott, E. R. D.

    2011-03-01

    New oxygen isotopic measurements of IIEs and H chondrites are indistinguishable — strengthening a possible common origin for these groups. Combining oxygen results with mineralogy, the nature of their parent body or bodies can be explored.

  13. Comparison of Pulse Sequences for R1–based Electron Paramagnetic Resonance Oxygen Imaging

    OpenAIRE

    Epel, Boris; Halpern, Howard J.

    2015-01-01

    Electron paramagnetic resonance (EPR) spin-lattice relaxation (SLR) oxygen imaging has proven to be an indispensable tool for assessing oxygen partial pressure in live animals. EPR oxygen images show remarkable oxygen accuracy when combined with high precision and spatial resolution. Developing more effective means for obtaining SLR rates is of great practical, biological and medical importance. In this work we compared different pulse EPR imaging protocols and pulse sequences to establish ad...

  14. Oxygenic photosynthesis without galactolipids

    OpenAIRE

    Awai, Koichiro; Ohta, Hiroyuki; Sato, Naoki

    2014-01-01

    Cyanobacteria, as well as chloroplasts of plants and algae, are the sites of photosynthesis that produces oxygen. Photosynthetic membranes, also known as thylakoid membranes, in these organisms contain galactolipids, without exception, as the major components. Galactolipids are thus believed to be important for photosynthesis or at least for the formation of the flattened shape of thylakoid membranes. The biosynthetic pathway of galactolipids is definitely different in plants and cyanobacteri...

  15. SINGLET OXYGEN IN NATURAL WATERS

    Science.gov (United States)

    Singlet oxygen is a reactive, electronically excited form of molecular oxygen that rapidly oxidizes a wide variety of organic substances, such as the polycyclic aromatics in petroleum hydrocarbon and the amino acids, histidine, tryptophan, and methionine. Studies of water samples...

  16. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orion Propulsion, Inc. proposes to develop an Oxygen and Methane RCS Thruster to advance the technology of alternate fuels. A successful Oxygen/CH4 RCS Thruster...

  17. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  18. Therapeutic reactive oxygen generation.

    Science.gov (United States)

    Scharff, Peter; Ritter, Uwe; Matyshevska, Olga P; Prylutska, Svitlana V; Grynyuk, Iryna I; Golub, Alexandr A; Prylutskyy, Yuriy I; Burlaka, Anatoliy P

    2008-01-01

    An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica particles to generate reactive oxygen species (ROS) in cells of two types (rat thymocytes, and transformed cells of ascite Erlich carcinoma, EAC, and leucosis L1210) is demonstrated. The damaging effect of photo excited C60-composites are shown, which appeared to be selective and manifested in transformed cells, but not in thymocytes. It has been shown that after the irradiation of aqueous solutions or cell suspensions in the presence of fullerene C60, the generation of reactive oxygen species is observed. It has been shown that the influence of photo excited fullerene C60 on metabolic processes depends on the composition of C60-containing complex and on the type of the cells. The damaging effects of photo excited fullerene C60-containing composites were demonstrated to be selective. The data presented suggest that the application of fullerene C60-containing composites for the selective activation of ROS-dependent death program in certain types of tumor cells is very promising. PMID:18564617

  19. Limitations of potentiometric oxygen sensors operating at low oxygen levels

    DEFF Research Database (Denmark)

    Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels;

    2011-01-01

    The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10...... oxygen sensors can be used....

  20. Oxygen Transport Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  1. Mixed oxygen ion/electron-conducting ceramics for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.W.; Armstrong, T.R.; Armstrong, B.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Mixed oxygen ion and electron-conducting ceramics are unique materials that can passively separate high purity oxygen from air. Oxygen ions move through a fully dense ceramic in response to an oxygen concentration gradient, charge-compensated by an electron flux in the opposite direction. Compositions in the system La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y{minus}z}Fe{sub y}N{sub z}O{sub 3{minus}{delta}}, perovskites where M=Sr, Ca, and Ba, and N=Mn, Ni, Cu, Ti, and Al, have been prepared and their electrical, oxygen permeation, oxygen vacancy equilibria, and catalytic properties evaluated. Tubular forms, disks, and asymmetric membrane structures, a thin dense layer on a porous support of the same composition, have been fabricated for testing purposes. In an oxygen partial gradient, the passive oxygen flux through fully dense structures was highly dependent on composition. An increase in oxygen permeation with increased temperature is attributed to both enhanced oxygen vacancy mobility and higher vacancy populations. Highly acceptor-doped compositions resulted in oxygen ion mobilities more than an order of magnitude higher than yttria-stabilized zirconia. The mixed conducting ceramics have been utilized in a membrane reactor configuration to upgrade methane to ethane and ethylene. Conditions were established to balance selectivity and throughput in a catalytic membrane reactor constructed from mixed conducting ceramics.

  2. The long-term effect of ambulatory oxygen in normoxaemic COPD patients

    DEFF Research Database (Denmark)

    Ringbaek, Thomas; Martinez, Gerd; Lange, Peter

    2013-01-01

    To study the long-term benefits of ambulatory oxygen (AO) in combination with pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease (COPD) patients experiencing exertional desaturation.......To study the long-term benefits of ambulatory oxygen (AO) in combination with pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease (COPD) patients experiencing exertional desaturation....

  3. Oxygen transport and degradation processes in mixed conducting perovskites

    CERN Document Server

    Benson, S J

    2002-01-01

    surface exchange between the ceramic and oxygen ions in the carbon dioxide and water has been investigated using sup 1 sup 8 O isotopically labelled species combined with SIMS. Also presented in Part 2 is an overview of the principles involved in the application of MIEC ceramics in oxygen separation membranes, with respect to the optimisation of oxygen fluxes and membrane performance. The application of oxide ion conducting ceramics in solid oxide electrochemical devices, such as solid oxide fuel cells, air separation membranes and oxygen sensors, is an area currently of great commercial interest. Much recent research has focused on the optimisation of the structural and electrical properties of these ceramics. However little is known about the long term stability of these materials under the realistic operating conditions of the systems, and it is this concern which has provided the motivation for this project. The study has been divided into two sections. Part 1 deals with the measurement of the oxygen tran...

  4. Influence of chromium, oxygen, carbon and nitrogen on iron viscosity

    International Nuclear Information System (INIS)

    Kinetic viscosity of 70 beforehand melted iron samples with additions of chromium (up to 2%) and carbon (up to 1%) has been investigated. Different conditions of melting brought about differences in oxygen and nitrogen contents. Viscosity of most samples has been determined in the 1550-1650 deg C temperature range. It is stated that small additions to pure iron of each of the investigated elements (O, Cr, C, N) decrease its viscosity. Combined effect of these additions on viscosity is inadditive. Simultaneous introduction of oxygen and carbon may result in increase of melt viscosity. The same fact is observed at combined introduction of chromium and nitrogen. Simultaneous introduction of other impurities-chromium with oxygen or carbon, nitrogen with oxygen causes amplification of their individual effect. Reasons for the observed regularities result from changes in energies of interparticle interactions in the melt and therefore rebuilding of structure of its short-range order

  5. 依达拉奉和银杏叶提取物注射液联合高压氧治疗急性一氧化碳中毒后迟发性脑病疗效观察%The study of edaravone and extract of gingo biloba leaves injection combined hyperbaric oxygen for treatment of delayed encephalopathy after carbon monoxide poisoning

    Institute of Scientific and Technical Information of China (English)

    孙锡波; 陈澎; 高茜; 李炳选

    2011-01-01

    Objective To research the clinical curative effect of edaravone and extract of gingo biloba leaves injection combined hyperbaric oxygen for treatment of delayed encephalopathy after carbon monoxide poisoning (DEACMP). Methods Sixty-four patients with DEACMP were randomly divided into treatment group of 32 cases and control group of 32 cases. The basic treatments of two groups were identical. Based on the basic treatments, treatment group was treated with edaravone 30 mg/d, intravenously drip for 14 days, plug extract of gingo biloba leaves injection 70 mg/d, intravenously drip for 30 days. The changes of HDS were measured and the total effective rate were counted in two groups before and after treatment. Results The total effective rate in treatment group was 87.5% , and while control group was 62. 5%. The total effective rate had a significant difference in two groups (P<0.05). The improvement of HDS in the treatment group was more significant than that in control group (P< 0. 05). Conclusion Edaravone and extract of gingo biloba leaves injection combined hyperbaric oxygen has favorable cognitive effect on DEACMP.%目的 探讨依达拉奉、银杏叶提取物注射液联合高压氧治疗一氧化碳中毒后迟发性脑病(DEACMP)的临床疗效.方法 将2007年1月至2010年6月我院64例DEACMP患者完全随机分为治疗组及对照组,各32例.对照组给予高压氧等常规治疗,治疗30 d.治疗组在高压氧等常规治疗基础上加用依达拉奉30 mg/次,2次/d静脉滴注,连用14 d;银杏叶提取物注射液70 mg,加入0.9%氯化钠注射液250 ml静脉滴注,1次/d,连用30 d.治疗前后均用长谷川智能量表(HDS)检测智能评分,并统计2组治疗总有效率.结果 治疗组有效28例,总有效率为87.5%;对照组有效20例,总有效率为62.5%,2组疗效比较差异有统计学意义(x2=5.33,P<0.05),治疗组治疗后HDS评分明显高于对照组[治疗后15 d:(13.6±2.3)分比(9.4±2.1)分,P<0.05;治疗后30 d:(19

  6. Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba.

    Science.gov (United States)

    Hoffmann, Friederike; Røy, Hans; Bayer, Kristina; Hentschel, Ute; Pfannkuchen, Martin; Brümmer, Franz; de Beer, Dirk

    2008-01-01

    The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges, which allows total oxygen consumption rates of 6-12 μmol cm(-3) sponge day(-1). Sponges of different sizes had similar diffusional uptake rates, which is explained by their similar surface/volume ratios. In pumping sponges, oxygen consumption rates were between 22 and 37 μmol cm(-3) sponge day(-1), and the entire tissue was oxygenated. Combining different approaches of direct oxygen measurement in living sponges with a dynamic model, we can show that tissue anoxia is a direct function of the pumping behavior. The sponge-microbe system of A. aerophoba thus has the possibility to switch actively between aerobic and anaerobic metabolism by stopping the water flow for more than 15 min. These periods of anoxia will greatly influence physiological variety and activity of the sponge microbes. Detailed knowledge about the varying chemical microenvironments in sponges will help to develop protocols to cultivate sponge-associated microbial lineages and improve our understanding of the sponge-microbe-system. PMID:24391232

  7. Oxygen transport and degradation processes in mixed conducting perovskites

    International Nuclear Information System (INIS)

    The application of oxide ion conducting ceramics in solid oxide electrochemical devices, such as solid oxide fuel cells, air separation membranes and oxygen sensors, is an area currently of great commercial interest. Much recent research has focused on the optimisation of the structural and electrical properties of these ceramics. However little is known about the long term stability of these materials under the realistic operating conditions of the systems, and it is this concern which has provided the motivation for this project. The study has been divided into two sections. Part 1 deals with the measurement of the oxygen transport properties of the mixed ionic-electronic conducting (MIEC) perovskite, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) using the oxygen isotope exchange-depth profiling technique, combined with Secondary Ion Mass Spectrometry (SIMS). The oxygen surface exchange data obtained from these measurements have enabled inferences to be made regarding the mechanism of the surface exchange process. Part 2 is concerned with the chemical stability of LSCF under the operating conditions of an oxygen separation membrane. The membrane may be operating at temperatures of 750-800 deg C, under an aggressive atmosphere of steam, carbon dioxide and oxygen. A study of the degradation of the material when exposed to these atmospheres for varying periods of time has been undertaken. The oxygen surface exchange between the ceramic and oxygen ions in the carbon dioxide and water has been investigated using 18O isotopically labelled species combined with SIMS. Also presented in Part 2 is an overview of the principles involved in the application of MIEC ceramics in oxygen separation membranes, with respect to the optimisation of oxygen fluxes and membrane performance. (author)

  8. Combination Light

    Science.gov (United States)

    1990-01-01

    The Rayovac TANDEM is an advanced technology combination work light and general purpose flashlight that incorporates several NASA technologies. The TANDEM functions as two lights in one. It features a long range spotlight and wide angle floodlight; simple one-hand electrical switching changes the beam from spot to flood. TANDEM developers made particular use of NASA's extensive research in ergonomics in the TANDEM's angled handle, convenient shape and different orientations. The shatterproof, water resistant plastic casing also draws on NASA technology, as does the shape and beam distance of the square diffused flood. TANDEM's heavy duty magnet that permits the light to be affixed to any metal object borrows from NASA research on rare earth magnets that combine strong magnetic capability with low cost. Developers used a NASA-developed ultrasonic welding technique in the light's interior.

  9. Oxygen therapy reduces postoperative tachycardia

    DEFF Research Database (Denmark)

    Stausholm, K; Kehlet, H; Rosenberg, J

    1995-01-01

    Concomitant hypoxaemia and tachycardia in the postoperative period is unfavourable for the myocardium. Since hypoxaemia per se may be involved in the pathogenesis of postoperative tachycardia, we have studied the effect of oxygen therapy on tachycardia in 12 patients randomly allocated to blinded...... air or oxygen by facemask on the second or third day after major surgery. Inclusion criteria were arterial hypoxaemia (oxygen saturation < or = 92%) and increased heart rate (> 90 beat.min-1). Each patient responded similarly to oxygen therapy: an increase in arterial oxygen saturation and a decrease...... in heart rate (p < 0.002). Thus, postoperative supplementary oxygen has a positive effect on the cardiac oxygen delivery and demand balance....

  10. Oxygen treatment of cluster headache

    DEFF Research Database (Denmark)

    Petersen, Anja S; Barloese, Mads C J; Jensen, Rigmor H

    2014-01-01

    PURPOSE: Our aim was to review the existing literature to document oxygen's therapeutic effect on cluster headache. METHOD: A PubMed search resulted in 28 hits, and from these and their references we found in total 11 relevant studies. We included six studies that investigated the efficacy of...... oxygen treatment. One study is observational and the remaining five are RCTs. Another five studies were on hyperbaric oxygen treatment hereof two case studies. CONCLUSION: Oxygen therapy can be administered at different flow rates. Three studies investigate the effect of low-flow oxygen, 6-7 l/min, and...... found a positive response in 56%, 75% and 82%, respectively, of the patients. One study investigates high-flow oxygen, 12 l/min, and found efficacy in 78% of attacks. The effect of hyperbaric oxygen therapy has been investigated in a few small studies and there is evidence only for an acute, but not a...

  11. Oxygen isotopes and lakes

    OpenAIRE

    Leng, Melanie; Dean, Jonathan

    2014-01-01

    Isotopes are variations of a particular chemical element. It is all to do with the number of neutrons. Oxygen has two main isotopes: 18O which has 10 neutrons and 8 protons; and 16O which has 8 neutrons and 8 protons. Although these variants have a different number of neutrons (and therefore a different atomic mass), the number of protons remains the same, and they are still classed as the same element. Isotopes are analysed in terms of ratios such as 18O/16O which is shortened to δ18O (δ...

  12. Mechanism of oxygen releasing of copper ferrite in the formation of the corresponding oxygen-deficient compound

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping; YU Bo; ZHANG Lei

    2009-01-01

    Copper ferrite is a promising material for hydrogen production through thermochemical water splitting. In this work, the cation distribution of copper ferrite and the corresponding oxygen-deficient compound of spinel structure was analyzed based on the crystal structural chemistry theory. The mechanism of oxygen releasing of CuO, Fe2O3, CuFe2O4 and metal (M=Ni, Mn or Zn) doped copper ferrite in the proc-ess of temperature rising was investigated by differential thermal analysis-thermogravimetry (DTA-TG). By combining the theoretical analysis with experimental results, the mechanism of oxygen releasing of copper ferrite is proposed, which is different from that of other ferrites. For copper ferrite, the oxygen releasing caused by Cu(Ⅱ)→Cu(I) plays a predominant role, while for other ferrites, the oxygen releas-ing resulting from Fe(ⅡI)→Fe(Ⅱ) is dominant.

  13. Mechanism of oxygen releasing of copper ferrite in the formation of the corresponding oxygen-deficient compound

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Copper ferrite is a promising material for hydrogen production through thermochemical water splitting.In this work,the cation distribution of copper ferrite and the corresponding oxygen-deficient compound of spinel structure was analyzed based on the crystal structural chemistry theory.The mechanism of oxygen releasing of CuO,Fe2O3,CuFe2O4 and metal(M=Ni,Mn or Zn) doped copper ferrite in the proc-ess of temperature rising was investigated by differential thermal analysis-thermogravimetry(DTA-TG).By combining the theoretical analysis with experimental results,the mechanism of oxygen releasing of copper ferrite is proposed,which is different from that of other ferrites.For copper ferrite,the oxygen releasing caused by Cu(Ⅱ)→Cu(Ⅰ) plays a predominant role,while for other ferrites,the oxygen releas-ing resulting from Fe(Ⅲ)→Fe(Ⅱ) is dominant.

  14. Timescales of Oxygenation Following the Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Ward, Lewis M.; Kirschvink, Joseph L.; Fischer, Woodward W.

    2016-03-01

    Among the most important bioenergetic innovations in the history of life was the invention of oxygenic photosynthesis—autotrophic growth by splitting water with sunlight—by Cyanobacteria. It is widely accepted that the invention of oxygenic photosynthesis ultimately resulted in the rise of oxygen by ca. 2.35 Gya, but it is debated whether this occurred more or less immediately as a proximal result of the evolution of oxygenic Cyanobacteria or whether they originated several hundred million to more than one billion years earlier in Earth history. The latter hypothesis involves a prolonged period during which oxygen production rates were insufficient to oxidize the atmosphere, potentially due to redox buffering by reduced species such as higher concentrations of ferrous iron in seawater. To examine the characteristic timescales for environmental oxygenation following the evolution of oxygenic photosynthesis, we applied a simple mathematical approach that captures many of the salient features of the major biogeochemical fluxes and reservoirs present in Archean and early Paleoproterozoic surface environments. Calculations illustrate that oxygenation would have overwhelmed redox buffers within ~100 kyr following the emergence of oxygenic photosynthesis, a geologically short amount of time unless rates of primary production were far lower than commonly expected. Fundamentally, this result arises because of the multiscale nature of the carbon and oxygen cycles: rates of gross primary production are orders of magnitude too fast for oxygen to be masked by Earth's geological buffers, and can only be effectively matched by respiration at non-negligible O2 concentrations. These results suggest that oxygenic photosynthesis arose shortly before the rise of oxygen, not hundreds of millions of years before it.

  15. Malignant brain tumor treatments and hyperbaric oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Kohshi, Kiyotaka [Univ. of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan)

    2000-09-01

    Malignant brain tumor treatment and hyperbaric oxygenation: Combined hyperbaric oxygenation (HBO) therapy and radiation therapy of malignant gliomas is reviewed. Malignant glioma tissue is hypoxic, and the efficacy of radiation therapy is increased by raising the oxygen density in glioma tissue. Residual tumor was reduced by a radiation dose of approximately 40 Gy in many cases when radiation therapy was begun within 15 minutes after HBO. In the experiment in animal models with different hypoxic fractions (HFs) of cells (SCCVII and 9L gliosarcoma), the tumor reduction effect was more significant in the SCCVII model, which has a higher HF. When the SCCVII model was irradiated within 30 minutes after HBO, the improvement effect was more significant (1.60-1.78 times) than by irradiation alone. HBO was effective in the treatment of radionecrosis of the brain. However, there were some cases in which radionecrosis progressed when the HBO treatments were discontinued, and the optimal duration of HBO treatment should be determined. It is difficult to differentiate between radionecrosis and tumor recurrence after radiosurgery of a malignant intracranial tumor. When no lesion reduction is observed in response to HBO treatment and steroid administration for about one month, the lesion is concluded to be a recurrence of the tumor, and additional irradiation should be performed. HBO treatment in combination with chemotherapy is also discussed. (K.H.)

  16. Malignant brain tumor treatments and hyperbaric oxygenation

    International Nuclear Information System (INIS)

    Malignant brain tumor treatment and hyperbaric oxygenation: Combined hyperbaric oxygenation (HBO) therapy and radiation therapy of malignant gliomas is reviewed. Malignant glioma tissue is hypoxic, and the efficacy of radiation therapy is increased by raising the oxygen density in glioma tissue. Residual tumor was reduced by a radiation dose of approximately 40 Gy in many cases when radiation therapy was begun within 15 minutes after HBO. In the experiment in animal models with different hypoxic fractions (HFs) of cells (SCCVII and 9L gliosarcoma), the tumor reduction effect was more significant in the SCCVII model, which has a higher HF. When the SCCVII model was irradiated within 30 minutes after HBO, the improvement effect was more significant (1.60-1.78 times) than by irradiation alone. HBO was effective in the treatment of radionecrosis of the brain. However, there were some cases in which radionecrosis progressed when the HBO treatments were discontinued, and the optimal duration of HBO treatment should be determined. It is difficult to differentiate between radionecrosis and tumor recurrence after radiosurgery of a malignant intracranial tumor. When no lesion reduction is observed in response to HBO treatment and steroid administration for about one month, the lesion is concluded to be a recurrence of the tumor, and additional irradiation should be performed. HBO treatment in combination with chemotherapy is also discussed. (K.H.)

  17. Composite oxygen transport membrane

    Science.gov (United States)

    Christie, Gervase Maxwell; Lane, Jonathan A.

    2014-08-05

    A method of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1-xA.sub.x).sub.wCr.sub.1-yB.sub.yO.sub.3-.delta. and a doped zirconia. In the porous fuel oxidation layer and the optional porous surface exchange layer, A is Calcium and in the dense separation layer A is not Calcium and, preferably is Strontium. Preferred materials are (La.sub.0.8Ca.sub.0.2).sub.0.95Cr.sub.0.5Mn.sub.0.5O.sub.3-.delta. for the porous fuel oxidation and optional porous surface exchange layers and (La.sub.0.8Sr.sub.0.2).sub.0.95Cr.sub.0.5Fe.sub.0.5O.sub.3-.delta. for the dense separation layer. The use of such materials allows the membrane to sintered in air and without the use of pore formers to reduce membrane manufacturing costs. The use of materials, as described herein, for forming the porous layers have application for forming any type of porous structure, such as a catalyst support.

  18. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    AnthonyRichardBain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  19. Sterilization by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Adir Jose; Mansano, Ronaldo Domingues; Andreoli Pinto, Terezinha de Jesus; Ruas, Ronaldo; Silva Zambon, Luis da; Silva, Monica Valero da; Verdonck, Patrick Bernard

    2004-07-31

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy.

  20. Sterilization by oxygen plasma

    International Nuclear Information System (INIS)

    The use of polymeric medical devices has stimulated the development of new sterilization methods. The traditional techniques rely on ethylene oxide, but there are many questions concerning the carcinogenic properties of the ethylene oxide residues adsorbed on the materials after processing. Another common technique is the gamma irradiation process, but it is costly, its safe operation requires an isolated site and it also affects the bulk properties of the polymers. The use of a gas plasma is an elegant alternative sterilization technique. The plasma promotes an efficient inactivation of the micro-organisms, minimises the damage to the materials and presents very little danger for personnel and the environment. Pure oxygen reactive ion etching type of plasmas were applied to inactivate a biologic indicator, the Bacillus stearothermophilus, to confirm the efficiency of this process. The sterilization processes took a short time, in a few minutes the mortality was complete. In situ analysis of the micro-organisms' inactivating time was possible using emission spectrophotometry. The increase in the intensity of the 777.5 nm oxygen line shows the end of the oxidation of the biologic materials. The results were also observed and corroborated by scanning electron microscopy

  1. Fires and Burns Involving Home Medical Oxygen

    Science.gov (United States)

    ... nfpa.org Fires and Burns Involving Home Medical Oxygen The air is normally 21% oxygen. Oxygen is not flammable, but fire needs it to burn. ¾ When more oxygen is present, any fire that starts will burn ...

  2. Seasonal oxygen depletion in the North Sea, a review.

    Science.gov (United States)

    Topcu, H D; Brockmann, U H

    2015-10-15

    Seasonal mean oxygen depletion in offshore and coastal North Sea bottom waters was shown to range between 0.9 and 1.8 mg/L, corresponding to 95-83% saturation, between July and October over a 30-year assessment period (1980-2010). The magnitude of oxygen depletion was controlled by thermal stratification, modulated by water depth and nitrogen availability. Analyses were based on about 19,000 combined data sets. Eutrophication problem areas were identified mainly in coastal waters by oxygen minima, the lower 10th percentile of oxygen concentrations, and deviations of oxygen depletion from correlated stratification values. Connections between oxygen consumption and nitrogen sources and conversion, including denitrification, were indicated by correlations. Mean oxygen consumption reflected a minimum seasonal turnover of 3.1 g N/m(2) in the south-eastern North Sea, including denitrification of 1 g N/m(2). Oxygen depletion was underestimated in shallow coastal waters due to repeated erosion of stratification as indicated by local high variability. PMID:26234616

  3. Curative effect observations of paroxetine combined with hyerbaric oxygen in patients of depression with sleep disorders%帕罗西汀联合高压氧治疗抑郁症患者睡眠障碍的临床疗效

    Institute of Scientific and Technical Information of China (English)

    胡蕊; 王志峰; 游道峰; 李幼东; 王冉; 王岚; 王学义

    2013-01-01

    Objective To observe the curative effect of paroxetine combined with hyperbaric oxygen in treatment of depression in patients with sleep disorders. Methods A total of 80 patients with sleep disorder of depression were randomly divided into control group and observation group, each group had forty patients, the two groups of patients were given paroxetine therapy , observation group was separately given hyperbaric oxygen treatment , the course was four weeks in both groups. The curative effect was compared between two groups of patients, HAMD scale score was observed and recorded in two groups of patients with sleep latency, total sleep time and wake-up time and the number of awakening. Results After four weeks' treatment,the observation group in comparison with control group was statistically significant in sleep latency,total sleep time and wake-up time and the number of awakening, respectively sleep latency (0. 50 ± 0. 23) h vs (2. 55 ±1. 43) h, total sleep time (7. 35 ±4. 45) h vs (3. 76 ±2. 32) h, wake-up time (1. 20 ± 0. 82) h vs (3. 15 ± 2. 13) h,the number of awakening (1.91 ± 1. 38) times vs (3. 48± 1. 25) times( P <0. 01). The two groups in comparison showed statistical significance in HAMD scale score,the clinical cure rate and the incidence of adverse reactions, respectively HAMD scale score (6.69 ± 5.01) marks vs (14.85 ± 5.46) marks , the clinical cure rate 95.0% vs 77. 5 % , the incidence of adverse reactions 7.5% vs 27.5%(P <0.05 or < 0. 01). Conclusion Paroxetine combined with hyperbaric oxygen in treatment of depression with sleep disorders works faster,sleep disorder symptoms are improved obviously, the two joint application shows good effect, reduces the incidence of adverse reactions.%目的 观察帕罗西汀联合高压氧治疗郁症患者睡眠障碍临床疗效.方法 选择80例伴有睡眠障碍的抑郁症患者,随机分为对照组和观察组,每组40例,两组患者均给予帕罗西汀治疗,观察

  4. Functional Oxygen Sensitivity of Astrocytes.

    Science.gov (United States)

    Angelova, Plamena R; Kasymov, Vitaliy; Christie, Isabel; Sheikhbahaei, Shahriar; Turovsky, Egor; Marina, Nephtali; Korsak, Alla; Zwicker, Jennifer; Teschemacher, Anja G; Ackland, Gareth L; Funk, Gregory D; Kasparov, Sergey; Abramov, Andrey Y; Gourine, Alexander V

    2015-07-22

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2 ) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental animal (rats and mice) study shows that astrocytes, the most numerous brain glial cells, are sensitive to physiological changes in PO2 . Astrocytes respond to decreases in PO2 a few millimeters of mercury below normal brain oxygenation with elevations in intracellular calcium ([Ca(2+)]i). The hypoxia sensor of astrocytes resides in the mitochondria in which oxygen is consumed. Physiological decrease in PO2 inhibits astroglial mitochondrial respiration, leading to mitochondrial depolarization, production of free radicals, lipid peroxidation, activation of phospholipase C, IP3 receptors, and release of Ca(2+) from the intracellular stores. Hypoxia-induced [Ca(2+)]i increases in astrocytes trigger fusion of vesicular compartments containing ATP. Blockade of astrocytic signaling by overexpression of ATP-degrading enzymes or targeted astrocyte-specific expression of tetanus toxin light chain (to interfere with vesicular release mechanisms) within the brainstem respiratory rhythm-generating circuits reveals the fundamental physiological role of astroglial oxygen sensitivity; in low-oxygen conditions (environmental hypoxia), this mechanism increases breathing activity even in the absence of peripheral chemoreceptor oxygen sensing. These results demonstrate that astrocytes are functionally specialized CNS oxygen sensors tuned for rapid detection of physiological changes in brain oxygenation. Significance statement: Most, if not all, animal cells possess mechanisms that allow them to

  5. An experimental set-up to analyse the oxygen consumption of elastomers during ageing by using a differential oxygen analyser

    Science.gov (United States)

    Herzig, Alexander; Johlitz, Michael; Lion, Alexander

    2015-11-01

    Ageing of polymers becomes more and more important. This can be seen by the increasing number of research projects dealing with this topic. However, the influence of oxygen on changes in the mechanical performance is undisputable and important with respect to the lifetime of polymer products. Therefore, a respirometer offers the potential to detect the smallest amounts of oxygen changes in the polymers' ambient air. It will be used to analyse the oxygen consumption of rubber which is exposed for different times to elevated temperatures. In this contribution, virgin rubber samples are aged for various times in a sealed chamber at temperatures of 60, 80 and 100°C. The decline of the oxygen concentration in the ambient air is measured by flushing the chamber with dried and cleaned air which is conducted into the respirometer. The oxygen concentration is compared with that in a reference chamber, which is exposed to the same ageing conditions as the sample under investigation. The absorbed oxygen is relevant for ageing and a considerable factor for further investigations. For this reason, an experimental set-up using a differential oxygen analyser is developed, which allows for ageing several samples simultaneously in external climate chambers. The comparison of the change in the mechanical material behaviour after ageing can provide an important contribution for improving constitutive models or ongoing researches on the fatigue strength of polymers. This work shows the development of an improved method for combining mechanical testing and the measurement of oxygen consumption.

  6. Ultra-sensitive optical oxygen sensors for characterization of nearly anoxic systems.

    Science.gov (United States)

    Lehner, Philipp; Staudinger, Christoph; Borisov, Sergey M; Klimant, Ingo

    2014-01-01

    Oxygen quantification in trace amounts is essential in many fields of science and technology. Optical oxygen sensors proved invaluable tools for oxygen measurements in a broad concentration range, but until now neither optical nor electrochemical oxygen sensors were able to quantify oxygen in the sub-nanomolar concentration range. Herein we present new optical oxygen-sensing materials with unmatched sensitivity. They rely on the combination of ultra-long decaying (several 100 ms lifetime) phosphorescent boron- and aluminium-chelates, and highly oxygen-permeable and chemically stable perfluorinated polymers. The sensitivity of the new sensors is improved up to 20-fold compared with state-of-the-art analogues. The limits of detection are as low as 5 p.p.b., volume in gas phase under atmospheric pressure or 7 pM in solution. The sensors enable completely new applications for monitoring of oxygen in previously inaccessible concentration ranges. PMID:25042041

  7. Formation of surface oxides and Ag2O thin films with atomic oxygen on Ag(111)

    Science.gov (United States)

    Derouin, Jonathan; Farber, Rachael G.; Heslop, Stacy L.; Killelea, Daniel R.

    2015-11-01

    The nature of the oxygen species adsorbed to silver surfaces is a key component of the heterogeneously catalyzed epoxidation of ethylene and partial oxidation of methanol over silver catalysts. We report the formation of two different silver-oxygen species depending on the flux and energy of incident gas-phase oxygen atoms on an Ag(111) surface. A combination of surface science techniques was used to characterize the oxidized surfaces. Atomic oxygen was generated with an Ir filament; lower temperatures created surface oxides previously reported. When O was deposited with a higher filament temperature, the surface became highly corrugated, little subsurface oxygen was observed, and thin layers of Ag2O were likely formed. These results show that the energy and flux of oxygen are important parameters in the chemical identity and abundance of oxygen on silver surfaces and suggest that formation of the Ag2O thin film hinders formation of subsurface oxygen.

  8. Ultra-sensitive optical oxygen sensors for characterization of nearly anoxic systems

    Science.gov (United States)

    Lehner, Philipp; Staudinger, Christoph; Borisov, Sergey M.; Klimant, Ingo

    2014-07-01

    Oxygen quantification in trace amounts is essential in many fields of science and technology. Optical oxygen sensors proved invaluable tools for oxygen measurements in a broad concentration range, but until now neither optical nor electrochemical oxygen sensors were able to quantify oxygen in the sub-nanomolar concentration range. Herein we present new optical oxygen-sensing materials with unmatched sensitivity. They rely on the combination of ultra-long decaying (several 100 ms lifetime) phosphorescent boron- and aluminium-chelates, and highly oxygen-permeable and chemically stable perfluorinated polymers. The sensitivity of the new sensors is improved up to 20-fold compared with state-of-the-art analogues. The limits of detection are as low as 5 p.p.b., volume in gas phase under atmospheric pressure or 7 pM in solution. The sensors enable completely new applications for monitoring of oxygen in previously inaccessible concentration ranges.

  9. Ultra-sensitive optical oxygen sensors for characterisation of nearly anoxic systems

    Science.gov (United States)

    Lehner, Philipp; Staudinger, Christoph; Borisov, Sergey M.; Klimant, Ingo

    2014-01-01

    Oxygen quantification in trace amounts is essential in many fields of science and technology. Optical oxygen sensors proved invaluable tools for oxygen measurements in a broad concentration range but until now neither optical nor electrochemical oxygen sensors were able to quantify oxygen in the sub-nanomolar concentration range. Herein we present new optical oxygen sensing materials with unmatched sensitivity. They rely on the combination of ultra-long decaying (several hundred milliseconds lifetime) phosphorescent boron- and aluminium-chelates and highly oxygen-permeable and chemically stable perfluorinated polymers. The sensitivity of the new sensors is improved up to 20-fold compared to state-of-the-art analogues. The limits of detection are as low as 5 parts per billion, volume in gas phase under atmospheric pressure or 7 picomolar in solution. The sensors enable completely new applications for monitoring of oxygen in previously inaccessible concentration ranges. PMID:25042041

  10. A combined neuropsychological and brain imaging study of obstructive sleep apnea.

    OpenAIRE

    Yaouhi, Khalid; Bertran, Françoise; Clochon, Patrice; Mézenge, Florence; Denise, Pierre; Foret, Jean; Eustache, Francis; Desgranges, Béatrice

    2009-01-01

    Patients with obstructive sleep apnea (OSA) show neuropsychological impairments ranging from vigilance decrements, attentional lapses and memory gaps to decreased motor coordination, but their cognitive profile, and the origin of the impairments, remain unclear. We sought to establish the neuropsychological profile of 16 newly diagnosed apneics and to highlight both their morphological and functional brain abnormalities. We used an extensive neuropsychological test battery to investigate atte...

  11. Bifunctional alkaline oxygen electrodes

    Science.gov (United States)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  12. Demonstration of Oxygen and Carbon Monoxide Propellants for Mars Missions

    Science.gov (United States)

    Linne, Diane L.

    1997-01-01

    Currently, proposed planetary exploration missions must be small, with low costs and a short development time. Relatively high-risk technologies are being accepted for such missions if they meet these guidelines. For a Mars sample-return mission, one of the higher risk technologies is the use of return propellants produced from indigenous materials such as the Martian atmosphere. This consists of 96 percent carbon dioxide, which can be processed into oxygen and carbon monoxide. This year, the NASA Lewis Research Center completed the experimental evaluation and subscale technology development of an oxygen/carbon monoxide propellant combination. Previous research included ignition characterization, combustion performance, and heat transfer characterization with gaseous propellants at room temperature. In this year s tests, we studied the ignition characteristics and combustion of oxygen and carbon monoxide at near liquid temperatures. The mixture ratio boundaries for oxygen and carbon monoxide were determined as a function of propellant temperature in a spark torch igniter. With both propellants at room temperature, the ignition range was between 0.50 and 1.44; and with both propellants chilled to near-liquid temperatures, it was between 2.4 and 3.1. Statistical analysis of the mean value of the ignition boundaries provided models that describe the combination of oxygen temperature, carbon monoxide temperature, and mixture ratio that resulted in ignition. This range is the larger boxed area shown in the figure. The smaller boxed area indicates the range at which there is a 90-percent confidence that ignition will occur. The relatively small range at only 90-percent confidence indicates that using the oxygen/carbon monoxide combination as its own ignition source may not be the best design for a remote engine operating on Mars. Tests also were performed in a simulated small rocket engine that used oxygen/hydrogen combustion gases as the ignition source for oxygen

  13. Analysis on the effect of hyperbaric oxygen combined with swallowing function training on the recovery of dysphagia following acute stroke%高压氧联合吞咽功能训练对急性脑卒中后吞咽障碍的康复效果分析

    Institute of Scientific and Technical Information of China (English)

    王丽华; 柳尧花

    2014-01-01

    目的 探讨高压氧(hyperbaric oxygen,HBO)治疗联合吞咽功能训练对急性脑卒中后吞咽功能障碍患者的康复效果及机制.方法 经患者知情同意,并经医院伦理委员会批准后,将68例患者分为HBO治疗组(HBO组)和对照组,每组34例,2组均行常规药物治疗和吞咽训练,治疗组在此基础上加用HBO治疗.2组治疗前、治疗后1个月进行洼田氏饮水评分、藤岛一郎吞咽(VFS)评分,并用经颅多普勒(TCD)检测治疗前后脑血流.结果 洼田氏饮水评分、VFS评分显示,2组患者的吞咽障碍治疗后均较治疗前明显改善(HBO组P<0.01,对照组P<0.05);与对照组比,HBO组治疗后改善较更明显.洼田氏饮水评分:治疗前4.05±0.91,治疗后1.68±0.54;VFS评分:治疗前3.96±1.29,治疗后7.15±1.93(均P<0.01).TCD检查结果显示,2组治疗后较治疗前脑血流量明显增加(治疗组P<0.01,对照组P<0.05).结论 HBO治疗对急性脑卒中后吞咽功能障碍患者康复效果显著,并能改善脑血流量.%Objective To explore the effect of hyperbaric oxygen (HBO) combined with swallowing function training on the recovery of dysphagia following acute stroke and also to analyze the mechanism involved.Methods With the knowledge and consent of the patients and following approval by the Hospital Ethics Committee,68 patients were divided into the HBO group and the control group,each consisting of 34 patients.The two groups all received routine drug therapy and swallowing function training,but the HBO group had supplementary HBO treatment in addition to drug therapy.Scores of WaTian's Drinking Water and Cane Island Ichiro Swallowing (VFS) were assessed for the 2 groups both before and after treatment,and 1 month after treatment.Transcranial Doppler (TCD) detection was made to monitor cerebral blood flow both before and after treatment.Results After treatment,scores of WaTian 's Drinking Water and Cane Island Ichiro Swallowing (VFS) for the 2 groups were

  14. Oxygen-reducing catalyst layer

    Science.gov (United States)

    O'Brien, Dennis P.; Schmoeckel, Alison K.; Vernstrom, George D.; Atanasoski, Radoslav; Wood, Thomas E.; Yang, Ruizhi; Easton, E. Bradley; Dahn, Jeffrey R.; O'Neill, David G.

    2011-03-22

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  15. Retinal oxygen extraction in humans

    Science.gov (United States)

    Werkmeister, René M.; Schmidl, Doreen; Aschinger, Gerold; Doblhoff-Dier, Veronika; Palkovits, Stefan; Wirth, Magdalena; Garhöfer, Gerhard; Linsenmeier, Robert A.; Leitgeb, Rainer A.; Schmetterer, Leopold

    2015-01-01

    Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measurements were done on 8 healthy subjects while breathing ambient room air and 100% oxygen. Total retinal blood flow was 44.3 ± 9.0 μl/min during baseline and decreased to 18.7 ± 4.2 μl/min during 100% oxygen breathing (P < 0.001) resulting in a pronounced decrease in retinal oxygen extraction from 2.33 ± 0.51 μl(O2)/min to 0.88 ± 0.14 μl(O2)/min during breathing of 100% oxygen. The method presented in this paper may have significant potential to study oxygen metabolism in hypoxic retinal diseases such as diabetic retinopathy. PMID:26503332

  16. Oxygen diffusion and oxygen effect in tumor tissue

    International Nuclear Information System (INIS)

    The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG)

  17. Co/CoO nanoparticles immobilized on Co-N-doped carbon as trifunctional electrocatalysts for oxygen reduction, oxygen evolution and hydrogen evolution reactions.

    Science.gov (United States)

    Zhang, Xian; Liu, Rongrong; Zang, Yipeng; Liu, Guoqiang; Wang, Guozhong; Zhang, Yunxia; Zhang, Haimin; Zhao, Huijun

    2016-05-21

    Co/CoO nanoparticles immobilized on Co-N-doped carbon were successfully developed using shrimp-shell derived N-doped carbon nanodots as precursors by a combined approach of polymerization and pyrolysis, as electrocatalysts exhibiting trifunctional catalytic activities toward oxygen reduction, oxygen evolution and hydrogen evolution reactions and high performance in rechargeable zinc-air batteries. PMID:27056374

  18. Body mass scaling of passive oxygen diffusion in endotherms and ectotherms.

    Science.gov (United States)

    Gillooly, James F; Gomez, Juan Pablo; Mavrodiev, Evgeny V; Rong, Yue; McLamore, Eric S

    2016-05-10

    The area and thickness of respiratory surfaces, and the constraints they impose on passive oxygen diffusion, have been linked to differences in oxygen consumption rates and/or aerobic activity levels in vertebrates. However, it remains unclear how respiratory surfaces and associated diffusion rates vary with body mass across vertebrates, particularly in relation to the body mass scaling of oxygen consumption rates. Here we address these issues by first quantifying the body mass dependence of respiratory surface area and respiratory barrier thickness for a diversity of endotherms (birds and mammals) and ectotherms (fishes, amphibians, and reptiles). Based on these findings, we then use Fick's law to predict the body mass scaling of oxygen diffusion for each group. Finally, we compare the predicted body mass dependence of oxygen diffusion to that of oxygen consumption in endotherms and ectotherms. We find that the slopes and intercepts of the relationships describing the body mass dependence of passive oxygen diffusion in these two groups are statistically indistinguishable from those describing the body mass dependence of oxygen consumption. Thus, the area and thickness of respiratory surfaces combine to match oxygen diffusion capacity to oxygen consumption rates in both air- and water-breathing vertebrates. In particular, the substantially lower oxygen consumption rates of ectotherms of a given body mass relative to those of endotherms correspond to differences in oxygen diffusion capacity. These results provide insights into the long-standing effort to understand the structural attributes of organisms that underlie the body mass scaling of oxygen consumption. PMID:27118837

  19. 磷酸肌酸钠联合高压氧治疗一氧化碳中毒迟发性脑病疗效观察%Curative effect observation of creatine phosphate sodium combined with high pressure oxygen in the treatment of chronic encephalopathy of carbon monoxide poisoning

    Institute of Scientific and Technical Information of China (English)

    李伟; 台立稳

    2016-01-01

    Objective:To explore the curative effect of creatine phosphate sodium combined with high pressure oxygen in the treatment of chronic encephalopathy of carbon monoxide poisoning(DEACMP).Methods:43 patients with DEACMP were selected. They were randomly divided into the treatment group and the control group.Patients in the control group were given conventional treatment.Patients in the treatment group were given injection creatine phosphate sodium treatment on the basis of the control group.The curative effects of two groups were observed.Results:The cure rate and effective rate of the treatment group were significantly higher than those of the control group,and the differences were statistically significant(P<0.05).Conclusion:The creatine phosphate sodium can improve the cell energy supply of DEACMP patients,protect the brain function,improve the hypoxia tolerance of brain cells,improve the life quality of DEACMP patients.%目的:探讨磷酸肌酸钠联合高压氧治疗一氧化碳中毒迟发性脑病(DEACMP)的疗效。方法:收治DEACMP患者43例,随机分为治疗组和对照组。对照组给予常规治疗,治疗组则在对照组的基础上加注射用磷酸肌酸钠治疗。观察两组患者的疗效。结果:治疗组治愈率及有效率均明显高于对照组,差异有统计学意义(P<0.05)。结论:磷酸肌酸钠可以改善DEACMP患者的细胞能量供应,保护脑功能,提高脑细胞对缺氧的耐受性,提高DEACMP患者的生活质量。

  20. Clinical applications of transcutaneous oxygen pressure combined with ankle-brachial index in Type 2 diabetics with peripheral arterial disease%经皮氧分压联合踝臂指数在2型糖尿病合并下肢动脉病变中的临床应用

    Institute of Scientific and Technical Information of China (English)

    李梦娟; 李素梅; 汝燕; 王芳; 王菊梅; 荆春艳; 王东; 董林; 任安

    2011-01-01

    目的:比较经皮氧分压(transcutaneous oxygen pressure,TcPO2)与踝臂指数(ankle--brachial index,ABI)在2型糖尿病(Type 2 diabetes mellitus,T2DM)合并下肢动脉病变(peripheral arterial disease,PAD)中的应用价值,探讨TcPO2与ABI在PAD诊断及治疗中的意义.方法:368例T2DM患者(男性188例,女性180例),采用多通道经皮氧分压检测仪测定足背TcPO2.依据TcPO2水平分为无受损组、轻度受损组、重度受损组.同时,采用彩色双功能超声诊断仪测定踝动脉压/肱动脉压比值即ABI,依据ABI水平分为无病变组(ABI≥0.9)和PAD组(ABI <0.9).结果:PAD组与无病变组相比,年龄增大,病程延长,合并冠心痛者增多,空腹血糖、餐后2h血糖、糖化血红蛋白、尿肌酐均升高,TcPO2减低(p<0.05).相关分析显示:年龄、病程、空腹血糖、三酰甘油、糖化血红蛋白Alc、体质量指数与TcPO2水平呈负相关(P<0.05),高密度脂蛋白、ABI与TcPO2水平呈正相关(P<0.05);TcPO2与ABI检测结果的符合率为93.9%,敏感度为90.2%,特异度约为95.2%.结论:随着年龄、病程的延长以及尿白蛋白肌酐比值的增加,糖尿病患者PAD程度越严重,PAD程度随着ABI和TcPO2减低而加重;TcPO2联合ABI对早期诊断糖尿病PAD具有较高的临床价值.%Objective To compare the clinical application in diagnosis and therapy for Type 2 diabetes patients with perpheral arterial diease ( PAD) between transcutaneous oxygen pressure ( TcPO2 ) determination and ankle-brachial index (ABI). Methods A total of 368 Type 2 diabetics (188 males and 180 females) were recruited into the study. TcPO2 of the acrotarsium was detected by multiple-channel transcutaneous tissue oxygen tension survey meter. According to die TcPO2 level, diese patients were divided into a non-injury group, a mild injury group, and a severe injury group. Moreover,the ankle artery pressure and brachial artery pressure were determined by Doppler color ultrasonography

  1. Steam reforming of light oxygenates

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Resasco, Daniel E; Jensen, Anker Degn

    2013-01-01

    distribution depended on the model compound, and C-3-oxygenates produced a larger fraction of by-products compared to C-2-oxygenates. Temperatures of 600 degrees C or above were generally needed to minimize the fraction of by-products and obtain a syngas containing mainly CO, CO2, H-2, and H2O with only traces...

  2. Measurement of forearm oxygen consumption

    DEFF Research Database (Denmark)

    Astrup, A; Simonsen, L; Bülow, J;

    1988-01-01

    blood flow and decreases skeletal muscle blood flow. This facilitates mixing of superficial blood with deep venous blood. Contralateral heating increased deep venous oxygen saturation and abolished the pronounced glucose-induced increase in oxygen consumption observed in the control experiments after...

  3. Oxygen Effects in Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Deshai Botheju

    2009-10-01

    Full Text Available Interaction of free oxygen in bio-gasification is a sparsely studied area, apart from the common argument of oxygen being toxic and inhibitory for anaerobic micro-cultures. Some studies have, however, revealed increased solubilisation of organic matter in the presence of some free oxygen in anaerobic digestion. This article analyses these counterbalancing phenomena with a mathematical modelling approach using the widely accepted biochemical model ADM 1. Aerobic oxidation of soluble carbon and inhibition of obligatory anaerobic organisms are modelled using standard saturation type kinetics. Biomass dependent first order hydrolysis kinetics is used to relate the increased hydrolysis rate with oxygen induced increase in biomass growth. The amended model, ADM 1-Ox (oxygen, has 25 state variables and 22 biochemical processes, presented in matrix form. The computer aided simulation tool AQUASIM 2.1 is used to simulate the developed model. Simulation predictions are evaluated against experimental data obtained using a laboratory batch test array comprising miniature anaerobic bio-reactors of 100 ml total volume each, operated under different initial air headspaces giving rise to the different oxygen loading conditions. The reactors were initially fed with a glucose solution and incubated at 35 Celsius, for 563 hours. Under the oxygen load conditions of 22, 44 and 88 mg/L, the ADM1-Ox model simulations predicted the experimental methane potentials quite adequately. Both the experimental data and the simulations suggest a linear reduction of methane potential with respect to the increase in oxygen load within this range.

  4. Mars oxygen production system design

    Science.gov (United States)

    Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

    1989-01-01

    The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

  5. Oxygen in the heliosphere

    Science.gov (United States)

    Luhmann, J. G.

    1994-01-01

    Oxygen within the heliosphere, whether neutral or ionized, comes from both the external source in the local interstellar medium (LISM) and internal sources. If transient cometary sources are neglected, Jupiter is the strongest of the internal sources by virtue of its corotation and charge exchange driven neutral wind. O(+) pickup ions are born where the penetrating neutrals lose an electron as a result of photoionization, charge exchange with solar wind protons, or solar wind electron impact ionization. The region of the heliosphere from which these pickup ions arise depends on the phase of the solar cycle as well as on the velocities of the neutrals. The present model of neutral O populations and their ionization suggests that Jovian pickup ions can dominate the inner heliospheric O(+) population if the LISM neutrals are strongly filtered at the heliopause, or are excluded by strong ionizing fluxes from the Sun. Other heliospheric species such as sulfur and nitrogen may have similar origins. These planetary sources need to be taken into account in the interpretation of interplanetary gas and ion composition observations.

  6. The Presence of Excess Oxygen in Burning Metallic Materials

    Science.gov (United States)

    Wilson, D. Bruce; Steinberg, Theodore A.; Stoltzfus, Joel M.; Fries, Joseph (Technical Monitor)

    2000-01-01

    Early work on burning of iron rods under conditions of the ATSM/NASA flammability test showed that there was excess oxygen, that is, above stoichiometric requirements for iron(III) oxide, present in the molten product during burning. Since that work, this phenomenon has been confirmed for burning under microgravity conditions and has been observed for a wide range of metals under burning conditions of a single micro-drop at ambient pressures and 20-second microgravity tests under pressurized oxygen-enriched conditions. This paper reviews these experimental observations and discusses the possible thermodynamic analysis for the metals iron, aluminum, and cobalt. The excess oxygen in the burning molten iron oxide was represented as combined to form a series of ferrite ions. For aluminum the excess oxygen is represented as a bridging species and a similar explanation is postulated for the cobalt system.

  7. Paradox reconsidered: Methane oversaturation in well-oxygenated lake waters

    DEFF Research Database (Denmark)

    Tang, Kam W.; McGinnis, Daniel F.; Frindte, Katharina;

    2014-01-01

    The widely reported paradox of methane oversaturation in oxygenated water challenges the prevailing paradigm that microbial methanogenesis only occurs under anoxic conditions. Using a combination of field sampling, incubation experiments, and modeling, we show that the recurring mid-water methane...... peak in Lake Stechlin, northeast Germany, was not dependent on methane input from the littoral zone or bottom sediment or on the presence of known micro-anoxic zones. The methane peak repeatedly overlapped with oxygen oversaturation in the seasonal thermocline. Incubation experiments and isotope...... analysis indicated active methane production, which was likely linked to photosynthesis and/or nitrogen fixation within the oxygenated water, whereas lessening of methane oxidation by light allowed accumulation of methane in the oxygen-rich upper layer. Estimated methane efflux from the surface water was...

  8. Microscopic oxygen imaging based on fluorescein bleaching efficiency measurements

    DEFF Research Database (Denmark)

    Beutler, Martin; Heisterkamp, Ines M.; Piltz, Bastian;

    2014-01-01

    Photobleaching of the fluorophore fluorescein in an aqueous solution is dependent on the oxygen concentration. Therefore, the time-dependent bleaching behavior can be used to measure of dissolved oxygen concentrations. The method can be combined with epi-fluorescence microscopy. The molecular...... states of the fluorophore can be expressed by a three-state energy model. This leads to a set of differential equations which describe the photobleaching behavior of fluorescein. The numerical solution of these equations shows that in a conventional wide-field fluorescence microscope, the fluorescence of...... fluorescein will fade out faster at low than at high oxygen concentration. Further simulation showed that a simple ratio function of different time-points during a fluorescence decay recorded during photobleaching could be used to describe oxygen concentrations in an aqueous solution. By careful choice of dye...

  9. Properties of Reactive Oxygen Species by Quantum Monte Carlo

    CERN Document Server

    Zen, Andrea; Guidoni, Leonardo

    2014-01-01

    The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal ...

  10. Oxygen detection using evanescent fields

    Science.gov (United States)

    Duan, Yixiang; Cao, Weenqing

    2007-08-28

    An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21.degree. C. to 35.degree. C. does not affect the net absorption of the sensor.

  11. Oxygen variability and meridional oxygen supply in the tropical North East Atlantic oxygen minimum zone

    Science.gov (United States)

    Hahn, Johannes; Brandt, Peter; Greatbatch, Richard J.; Krahmann, Gerd; Körtzinger, Arne

    2013-04-01

    The oxygen minimum zone (OMZ) of the tropical North East Atlantic (TNEA) is located between the oxygen-rich equatorial region and the Cape Verde Frontal Zone at about 20°N in a depth range of 300 - 700 m. Its horizontal extent is predominantly defined by the North Equatorial Current and by the equatorial zonal current system ventilating the region to the north and south of the OMZ, respectively. The interior of the OMZ is characterized by a sluggish flow regime, where mesoscale eddies play a major role in the ventilation. In this study we focus on the oxygen variability in the TNEA as well as the eddy driven lateral ventilation of the TNEA OMZ across its southern boundary. During recent years an intense measurement program was executed along 23°W cutting meridionally through the TNEA OMZ. Hydrographic and velocity data has been acquired from ship sections and moorings, together covering the latitude range between 6°S and 14°N with particularly high meridional resolution of shipboard and high temporal resolution of moored observations. Based on shipboard data we derived a meridional section of oxygen variance, which reveals numerous local maxima of oxygen variability. Exemplary, strong oxygen variability is observed at the upper (300m, 5° - 12°N) and the southern boundary (400m - 700m, 5°N - 8°N) of the OMZ, whereas the interior of the OMZ is characterized by weak variability. An application of the extended Osborn-Cox model shows that the strong oxygen variability at the southern boundary is mainly generated by mesoscale eddies. The strong variability at the upper boundary is generated by mesoscale eddies as well as microscale turbulence. We apply two methods to estimate the meridional oxygen flux: 1) a flux gradient parameterization and 2) a correlation of oxygen and velocity mooring time series. From the analysis of the 5°N mooring data we find a northward oxygen flux directed towards the OMZ at its core depth, that is mainly due to variability of

  12. CLINICAL EVALUATION OF DSA-GUIDING COMBINED USE OF OXYGEN-OZONE THERAPY WITH PERCUTANEOUS INTRADISCAL RADIOFREQUENCY THERMOCOAGULATION FOR THE TREATMENT OF CERVICAL DISC HERNIATIONS%DSA引导臭氧联合射频热凝术治疗颈椎间盘突出症的临床评价

    Institute of Scientific and Technical Information of China (English)

    孙琳; 杨晓秋; 周泽军; 刘茂林; 邓琼; 陈世玉

    2013-01-01

    目的:评价数字减影血管造影(digital subtraction angiography,DSA)引导经皮穿刺椎间盘臭氧联合射频热凝术治疗颈椎间盘突出症的临床疗效与安全性.方法:回顾性分析49例颈椎间盘突出症患者,分为两组:DSA引导经皮椎间盘臭氧联合射频热凝术组(O组,n=30),在DSA引导下行经皮椎间盘射频热凝术,5 min后经射频针于椎间盘内注射臭氧(浓度:40 ug/ml)5~8 ml; DSA引导经皮椎间盘射频热凝术组(P组,n=19),仅行颈椎间盘射频热凝术.根据疼痛视觉模拟评分量表(visual analogue scale,VAS)、改良MacNab评价法及患者满意度指标,在术后2周、1个月、3个月评估临床疗效,观察患者不良反应.结果:两组患者术后VAS评分与基线值相比均显著下降(P< 0.05),O组患者VAS评分较P组在2周、1个月、3个月显著降低(P<0.05);O组优良率在2周,1个月,3个月显著高于P组(P<0.05);O组患者满意度较P组显著提高(P<0.05).两组患者均无严重不良反应发生.结论:DSA引导经皮椎间盘臭氧联合射频热凝术治疗颈椎间盘突出症能更有效地降低患者疼痛评分,改善患者颈肩功能;患者满意度高于单纯经皮椎间盘射频热凝术.DSA引导下两种治疗方法的安全性均较高.%Objective: To evaluate the efficacy and security of DSA-guiding combined use of oxygen-ozone therapy with percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) for the treatment of cervical disc herniations. Methods: To analyze retrospectively the clinical material about 49 cases of patients with cervical disc herniations into two groups. P group (n = 19) received DSA-guiding PIRFT; 0 group (n = 30) received a combination of oxygen-ozone therapy after PIRFT. Primary outcome measures included visual analogue scale (VAS) for pain and the modified MacNab evaluation method, complication and patient's satisfaction. Clinical assessment of these outcome measures was performed at 2 weeks, 1

  13. Oxygen isotopes separation during fluorination of oxygen-containing compounds

    International Nuclear Information System (INIS)

    The mechanisms of separation of oxygen isotopes in the reaction of water with BrF5 and CoF3 and of calcium sulphate with CsBrF4 are considered. The reaction of water with BrF5 is accompanied by enrichment of the oxygen released with the light isotope 16O, and with CoF3, by enrichment with the heavy isotope 18O. The separation of the oxygen isotopes attending the reaction of water with CoF3 is due to the establishment of isotopic equilibrium between the oxygen and the intermediate reaction product, i.e. the hydroderivative of cobalt trifluoride (α=1.016 at 350 deg C). In the case of BrF5 a kinetic isotopic effect takes place (α=0.994sup(*) at 25 deg C and α=0.996 at 120 deg C), which is due to the preferential rupture of the H-16O bond (α is the separation coefficient). The incomplete release of oxygen in the form of O2 from CaSO4 does not lead to separation of the oxygen isotopes, probably becaused of the equivalence of all the peripheral oxygen atoms in the SO4-2 anion from the point of view of the reaction with CsBrF4

  14. Effect of oxygen concentration on singlet oxygen luminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Longchao; Lin, Lisheng; Li, Yirong; Lin, Huiyun; Qiu, Zhihai [MOE Key Laboratory of OptoElectronic Science and Technology for Medicine, Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China); Gu, Ying [Department of Laser Medicine, Chinese PLA General Hospital, Beijing 100853 (China); Li, Buhong, E-mail: bhli@fjnu.edu.cn [MOE Key Laboratory of OptoElectronic Science and Technology for Medicine, Fujian Provincial Key Laboratory for Photonics Technology, Fujian Normal University, Fuzhou 350007 (China)

    2014-08-01

    Singlet oxygen ({sup 1}O{sub 2}) is a major phototoxic component in photodynamic therapy (PDT) and its generation is dependent on the availability of tissue oxygen. To examine the effect of oxygen concentration on {sup 1}O{sub 2} detection, two hydrophilic photosensitizer (PS), rose bengal (RB) and meso-metra (N-methyl-4-pyridyl) porphine tetra tosylate (TMPyP) were used as model PS. Irradiation was carried out using 523 nm under hypoxic (2%, 13%), normoxic (21%) and hyperoxic (65%) conditions. The spectral and spatial resolved {sup 1}O{sub 2} luminescence was measured by near-infrared (NIR) photomultiplier tube (PMT) and camera, respectively. Upon the irradiation, the emission signal mainly consisted of background scattering light, PS fluorescence and phosphorescence, and {sup 1}O{sub 2} luminescence. The PS phosphorescence was evidently dependent on the oxygen concentration and PS type, which resulted in the change of emission profile of {sup 1}O{sub 2} luminescence. This change was further demonstrated on {sup 1}O{sub 2} luminescence image. The present study suggests that the low oxygen concentration could affect {sup 1}O{sub 2} luminescence detection. - Highlights: • Both spectral and spatial resolved {sup 1}O{sub 2} luminescence measurements were performed. • Effect of oxygen concentration on {sup 1}O{sub 2} generation was quantitatively evaluated. • Low oxygen concentration could affect {sup 1}O{sub 2} luminescence detection.

  15. Oxygen labelled CO2

    International Nuclear Information System (INIS)

    Tests were carried out as to whether additional information concerning pulmonary gas exchange could be obtained from the application of oxygen labelled carbon dioxide. Single breath experiments were performed on two healthy subjects with 0.1 percent C16O18O and 2.8 percent C18O2 in the inspiratory gas. Breath-hold time was varied between 0.5-20s in different experiments. The 18O-concentration of the end-expired gas bi-exponentially decreased with increasing breath-hold time. The high and low rate constants 4s-1 and 0.12s-1 for C18O2 and 2.5s-1 and 0.87s-1 for C16O18O were derived, respectively. These results, together with model calculations, suggest: 1) the rapid disappearance of C18O2 from the alveolar space is primarily limited by diffusion, so that this isotopic species can be applied to quantify pulmonary diffusing conditions; 2) the lower disappearance rate of C16O18O is caused by a lower equilibration kinetics in blood, so that this isotopic species offers a possibility to study carbonic anhydrase activity of the red cells in vivo; 3) the slow phase of label decay is influenced by both alveolar dead space and carbonic anhydrase activity of the pulmonary tissues. Pathological dead spaces are expected to be sensitively detectable by C16O18O as well as by C18O2. (author). 4 refs.; 4 figs

  16. Effects of oxygen concentration on the growth of Nannochloropsis sp.

    OpenAIRE

    Raso, S

    2013-01-01

    ANannochloropsissp. is a promising microalgal resource for production of food, feed and bio-based commodities, as it can grow relatively fast and combines high lipid content with high content of poly-unsaturated fatty acids. High productivity with constant product quality can be achieved in fully controlled closed photobioreactors. In these closed photobioreactors, however, oxygen accumulation occurs and causes inhibition of the growth by photorespiration combined with photoinhibition. The in...

  17. Effects of radiotherapy after hyperbaric oxygenation on malignant gliomas

    OpenAIRE

    Kohshi, K; Kinoshita, Y; Imada, H; Kunugita, N; Abe, H; Terashima, H; Tokui, N; Uemura, S

    1999-01-01

    The purpose of this non-randomized trial was to evaluate the efficacy of radiotherapy combined with hyperbaric oxygen (HBO) in patients with malignant glioma. Between 1987 and 1997, 29 patients in whom computerized tomography (CT) or magnetic resonance imaging (MRI) scans showed post-operative residual tumours were locally irradiated with nitrosourea-based chemotherapy. Treatments were consecutively combined with HBO at two institutions since 1991 and 1993. Fifteen patients were irradiated da...

  18. Oxygenates vs. synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  19. Oxygen consumption by hydrazine in long sample lines

    International Nuclear Information System (INIS)

    In nuclear power plants secondary side system dissolved oxygen concentration is a strictly controlled chemistry parameter intended to minimize corrosion and fouling of steam cycle components. Low dissolved oxygen concentration is maintained by a combination of mechanical de-aeration and chemical reaction. The dissolved oxygen concentration in feedwater is monitored by sampling systems to ensure it remains within station specification during operation. The sample lines in a nuclear power plant's sampling system can be from 5 to nearly 200 meters in length, resulting in sample residence times between the take-off point to the analyzer from a few seconds to several minutes, depending on the flow rate and the length of the sample line. For many chemical parameters the residence time is of no concern. For measurements of dissolved oxygen and hydrazine in the secondary coolant, however, for residence times longer than one minute, it is uncertain whether the sample is representative of conditions in the secondary coolant, especially for samples taken from locations where the temperature is well over 100 deg. C. To address this concern, a series of tests were conducted under both warm-up and power operation conditions, respectively, to investigate the effect of temperature, residence time, sample line length, surface area, hydrazine-to-oxygen ratio, and the concentrations of dissolved oxygen and hydrazine on the consumption of oxygen by hydrazine. The test results revealed that dissolved oxygen measurements in CANDU plants are underestimated to various degrees, depending on the sampling system operating conditions. Two distinct types of behaviours are observed for the oxygen removal rate: 1) the percentage removal of dissolved oxygen is invariant with time during the tests, and increases with increasing residence time in the test section, when the reaction between hydrazine and oxygen is better described by a homogenous reaction mechanism, and 2) the percentage oxygen

  20. Temporal variation of the oxygen flux in the inner magnetosphere

    Science.gov (United States)

    Beaujean, R.

    1995-01-01

    The intensity of oxygen ions in the inner magnetosphere was studied by several experiments using track detectors. This report combines the measurements on Soviet COSMOS satellites of the period 1985-1988 with earlier results from the SL-1 mission (1983). The evident temporal variation supports the conclusion that the orgin for these particles is trapping of the anomalous component.

  1. Universality in Oxygen Evolution Electrocatalysis on Oxide Surfaces

    DEFF Research Database (Denmark)

    Man, Isabela Costinela; Su, Hai-Yan; Vallejo, Federico Calle;

    2011-01-01

    Trends in electrocatalytic activity of the oxygen evolution reaction (OER) are investigated on the basis of a large database of HO* and HOO* adsorption energies on oxide surfaces. The theoretical overpotential was calculated by applying standard density functional theory in combination with the c...

  2. Effect of oxygen breathing and perfluorocarbon emulsion treatment on air bubbles in adipose tissue during decompression sickness

    DEFF Research Database (Denmark)

    Randsoe, T; Hyldegaard, O

    2009-01-01

    Decompression sickness (DCS) after air diving has been treated with success by means of combined normobaric oxygen breathing and intravascular perfluorocarbon (PFC) emulsions causing increased survival rate and faster bubble clearance from the intravascular compartment. The beneficial PFC effect...... breathing. The combined effect of oxygen breathing and PFC infusion neither prevented nor increased transient bubble growth time, rate, or growth ratio compared with oxygen breathing alone. We conclude that oxygen breathing in combination with PFC infusion causes faster bubble disappearance and does...... has been explained by the increased transport capacity of oxygen and inert gases in blood. However, previous reports have shown that extravascular bubbles in lipid tissue of rats suffering from DCS will initially grow during oxygen breathing at normobaric conditions. We hypothesize that the combined...

  3. Towards stable bifunctional oxygen electrodes and corrosion resistant gas diffusion layers for regenerative fuel cells

    OpenAIRE

    Silva, R A; Soares, C. O.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Pereira, M. I. da Silva; C. M. Rangel

    2013-01-01

    ABSTRACT: Regenerative fuel cells (RFCs) can provide very high energy storage at minimal weight in a dual mode system, by combining an electrolyzer and a fuel cell. Although RFCs are an appealing technology their development is still at an early stage. One key issue is the search for highly active electrocatalysts for both oxygen reduction and water oxidation. Presently, platinum is the best electrocatalyst for the oxygen reduction reaction (ORR), but has a poor oxygen evolution (OER) perform...

  4. Oxygen diffusion in cuprate superconductors

    International Nuclear Information System (INIS)

    Superconducting properties of the cuprate superconductors depend on the oxygen content of the material; the diffusion of oxygen is thus an important process in the fabrication and application of these materials. This article reviews studies of the diffusion of oxygen in La2-xSrxCuO4, YBa2Cu3O7-δ, YBa2Cu4O8, and the Bi2Sr2Can-1CunO2+4 (n = 1, and 2) superconductors, and attempt to elucidate the atomic mechanisms responsible

  5. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

    2003-11-01

    The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared

  6. What Are the Risks of Oxygen Therapy?

    Science.gov (United States)

    ... NHLBI on Twitter. What Are the Risks of Oxygen Therapy? Oxygen therapy can cause complications and side effects. These ... problem, your doctor may need to change your oxygen flow rate or the length of time you' ...

  7. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Two main innovations will be developed in the Phase II effort that are fundamentally associated with our gaseous oxygen/gaseous methane RCS thruster. The first...

  8. Modulation of tumor oxygenation

    International Nuclear Information System (INIS)

    There is a large body of evidence suggesting that deficiencies in the O2 supply of tumors exist due to restrictions (i) in the O2 delivery by perfusion and/or diffusion, and (ii) in the O2 transport capacity. Whereas the former are mostly based on inadequate and heterogeneous microcirculatory functions, the latter are predominantly due to tumor-associated anemia. Possible uses and limitations of measures are discussed which can increase the microvascular O2 content and thus may preferentially serve to enhance diffusion-limited O2 availability. In addition, means are described for improving and increasing the uniformity of microcirculation thus possibly enhancing perfusion-limited O2 delivery. Reducing cellular respiration rate should be of benefit in both pathophysiological conditions. Because both types of O2 limitation coexist in solid tumors, appropriate combinations should be aimed at eradicating tumor hypoxia which is present in at least one third of cancers in the clinical setting

  9. Oxygen transport kinetics of the misfit layered oxide Ca3Co4O9+d

    NARCIS (Netherlands)

    Thoréton, V.; Hu, Y.; Pirovano, C.; Capoen, E.; Nuns, N.; Mamede, A.S.; Dezanneau, G.; Yoo, C.-Y.; Bouwmeester, H.J.M.; Vannier, R.N.

    2014-01-01

    The oxygen transport kinetics of the misfit-layered cobaltite, Ca3Co4O9+d, known for its thermoelectric properties, was investigated by combined application of 18O/16O isotope exchange and electrical conductivity relaxation techniques. Although oxygen diffusion is found to be two orders of magnitude

  10. Single Cell Responses to Spatially Controlled Photosensitized Production of Extracellular Singlet Oxygen

    DEFF Research Database (Denmark)

    Pedersen, Brian Wett; Sinks, Louise E.; Breitenbach, Thomas;

    2011-01-01

    The response of individual HeLa cells to extracellularly produced singlet oxygen was examined. The spatial domain of singlet oxygen production was controlled using the combination of a membrane-impermeable Pd porphyrin-dendrimer, which served as a photosensitizer, and a focused laser, which serve...

  11. Ultralow Oxygen Treatment for Postharvest Control of Western Flower Thrips on Head Lettuce

    Science.gov (United States)

    Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae), were subjected to ULO treatments with different combinations of oxygen level, temperature, and treatment duration in plastic jars. Oxygen levels used ranged from 0.0015% to 0.01%. Temperatures ranged from 1 to 10°C. Treatme...

  12. Regional imaging with oxygen-14

    International Nuclear Information System (INIS)

    The metabolic significance of the distribution of labeled oxygen was studied in the dog by inhalation of gas mixtures labeled with oxygen-14 (T/sub 1/2/ = 71 seconds) maintained at a constant level of activity. Under steady-state conditions, whole-body images were developed by detection of the positron annihilation emissions with a dual head rectilinear scanner in the coincidence mode

  13. Oxygen Regulates Tissue Nitrite Metabolism

    OpenAIRE

    Curtis, Erin; Hsu, Lewis L.; Noguchi, Audrey C.; Geary, Lisa; Shiva, Sruti

    2012-01-01

    Aims: Once dismissed as an inert byproduct of nitric oxide (NO) auto-oxidation, nitrite (NO2-) is now accepted as an endocrine reservoir of NO that elicits biological responses in major organs. While it is known that tissue nitrite is derived from NO oxidation and the diet, little is known about how nitrite is metabolized by tissue, particularly at intermediate oxygen tensions. We investigated the rates and mechanisms of tissue nitrite metabolism over a range of oxygen concentrations. Results...

  14. Echocardiography in military oxygen divers.

    OpenAIRE

    Boussuges, Alain; Riera, Florence; Rossi, Pascal; Castagna, Olivier; Galland, François; Blatteau, Jean-Eric

    2007-01-01

    BACKGROUND: Oxygen divers undergo environmental stressors such as immersion, ventilation with scuba, cold exposure, and increased ambient pressure. All of these stressors may be responsible for acute hemodynamic modifications. We hypothesized that repeated hyperbaric hyperoxia exposure induces long-term cardiovascular modifications. METHODS: A Doppler echocardiography was conducted on 20 military oxygen divers (average 12 yr diving experience) and compared with 22 controls. Parameters known t...

  15. Active oxygens and their protection

    International Nuclear Information System (INIS)

    Most of radiation-induced damages to living organisms are thought to be originated from active oxygens produced from water and oxygen in living organisms by irradiation. These active oxygens react with various intracellular components including DNA, proteins, lipids, carbohydrates and other lower molecular weight substances, then finally induce genetic damages, metabolic damages or abnormality of cell functions. Our studies demonstrated that active oxygens produced by radiation caused peroxidation of biological membrane lipids, resulting in destruction of membrane structure and inactivation of membrane-bound enzymes. The lipid peroxidation might be also one of the most important factors to induce radiation carcinogenesis. Protective substances in several rat tissues and yeast against active oxygens produced by radiation were also investigated and a basic protein which have high content of SH group and three different lower molecular weight substances were separated from rat liver cytosol. These substances have functions to suppress not only radiation-induced lipid peroxidation but also radiation-induced inactivation of membrane-bound enzymes. From these data, effect of active oxygens produced by radiation and their protection in organisms are discussed. (author)

  16. Oxygen and Early Animal Evolution

    Science.gov (United States)

    Xiao, S.

    2012-12-01

    It is often hypothesized that the rise of animals was triggered by an increase in O2 levels in the atmosphere and oceans. However, this hypothesis is remarkably difficult to test, because the timing of animal divergences is poorly resolved, the physiology of early animals is often unknown, estimates of past pO2 levels come with large error bars, and causal relationships between oxygenation and animal evolution are difficult to establish. Nonetheless, existing phylogenetic, paleontological, and geochemical data indicate that the evolution of macroscopic animals and motile macrometazoans with energetically expensive lifestyles may be temporally coupled with ocean oxygenation events in the Ediacaran Period. Thus, it is plausible that ocean oxygenation may have been a limiting factor in the early evolution of macroscopic, complex, and metabolically aggressive animals (particularly bilaterian animals). However, ocean oxygenation and animal evolution were likely engaged in two-way interactions: Ediacaran oxygenation may have initially lifted a physiological barrier for the evolution of animal size, motility, and active lifestyles, but subsequent animal diversification in the Paleozoic may have also changed oceanic redox structures. Viewed in a broader context, the early evolutionary history of animals was contingent upon a series of events, including genetic preparation (developmental genetics), environmental facilitation (oceanic oxygenation), and ecological escalation (Cambrian explosion), but the rise of animals to ecological importance also had important geobiological impacts on oceanic redox structures, sedimentary fabrics, and global geochemical cycles.

  17. Inhibition of fungal growth with extreme low oxygen levels

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Haasum, Iben

    1998-01-01

    Fungal spoilage of foods is effectively controlled by removal of oxygen from the package, especially if this is combined with elevated carbon dioxide (CO2) levels. However, great uncertainty exist on just how low the residual oxygen levels in the package must be especially when carbon dioxide...... contaminants of a wide range of products, and to determine the limit of growthFungi isolated from a wide range of products were incubated for up to three weeks at 25oC , 90% relative humidity at 1.0, 0.5, 0.25, 0.1, and 0.05% oxygen respectively in a custom made incubator with an interlock system for...... Penicillia and Aspergilli were also inhibited by oxygen levels less than 0.5%, but less than 0.01% was required to efficiently inhibit these fungi. Most resistant to very low oxygen levels was the Fusarium species.These results shows that very low oxygen levels are required to avoid fungal growth in package...

  18. COMPARISON OF METHODS TO DETERMINE OXYGEN DEMAND FOR BIOREMEDIATION OF A FUEL CONTAMINATED AQUIFER

    Science.gov (United States)

    Four analytical methods were compared for estimating concentrations of fuel contaminants in subsurface core samples. The methods were total organic carbon, chemical oxygen demand, oil and grease, and a solvent extraction of fuel hydrocarbons combined with a gas chromatographic te...

  19. High resolution mapping of oxygen reduction reaction kinetics at polycrystalline platinum electrodes

    NARCIS (Netherlands)

    Chen, C.H.; Meadows, K.E.; Cuharuc, A.; Lai, S.C.S.; Unwin, P.R.

    2014-01-01

    The scanning droplet-based technique, scanning electrochemical cell microscopy (SECCM), combined with electron backscatter diffraction (EBSD), is demonstrated as a powerful approach for visualizing surface structure effects on the rate of the oxygen reduction reaction (ORR) at polycrystalline platin

  20. Co-evolution of eukaryotes and ocean oxygenation in the Neoproterozoic era

    Science.gov (United States)

    Lenton, Timothy M.; Boyle, Richard A.; Poulton, Simon W.; Shields-Zhou, Graham A.; Butterfield, Nicholas J.

    2014-04-01

    The Neoproterozoic era (about 1,000 to 542 million years ago) was a time of turbulent environmental change. Large fluctuations in the carbon cycle were associated with at least two severe -- possible Snowball Earth -- glaciations. There were also massive changes in the redox state of the oceans, culminating in the oxygenation of much of the deep oceans. Amid this environmental change, increasingly complex life forms evolved. The traditional view is that a rise in atmospheric oxygen concentrations led to the oxygenation of the ocean, thus triggering the evolution of animals. We argue instead that the evolution of increasingly complex eukaryotes, including the first animals, could have oxygenated the ocean without requiring an increase in atmospheric oxygen. We propose that large eukaryotic particles sank quickly through the water column and reduced the consumption of oxygen in the surface waters. Combined with the advent of benthic filter feeding, this shifted oxygen demand away from the surface to greater depths and into sediments, allowing oxygen to reach deeper waters. The decline in bottom-water anoxia would hinder the release of phosphorus from sediments, potentially triggering a potent positive feedback: phosphorus removal from the ocean reduced global productivity and ocean-wide oxygen demand, resulting in oxygenation of the deep ocean. That, in turn, would have further reinforced eukaryote evolution, phosphorus removal and ocean oxygenation.

  1. Effect of initial low oxygen stress combined with 1-methylcyclopropene in ‘Royal Gala’ apple quality stored under ultralow O2
    Efeito do estresse inicial por baixo O2 combinado com 1-metilciclopropeno na conservação de maçãs ‘Royal Gala’ armazenadas com ultrabaixo O2

    OpenAIRE

    Auri Brackmann; Rogério de Oliveira Anese; Anderson Weber; Vanderlei Both; Adriano Roque de Gasperin; Elizandra Pivotto Pavanello

    2013-01-01

    The aim of this study was evaluated initial low oxygen stress (ILOS) and the interaction with 1-methylcyclopropene (1-MCP) during ultralow oxygen (ULO) storage in maintenance of ‘Royal Gala’ apple quality. The experiment was conducted in a completely randomized design, with two-factor. Each ILOS was applied for 14 days with 0.4 kPa O2. The treatments evaluated were: [1] 1.2 kPa O2 + 2.0 kPa CO2 (control); [2] 0.6 kPa O2 + 1.0 kPa CO2 (without stress); [3] 0.6 kPa O2 + 1.0 kPa CO2 (one stress)...

  2. Real-Time Monitoring of Singlet Oxygen and Oxygen Partial Pressure During the Deep Photodynamic Therapy In Vitro.

    Science.gov (United States)

    Li, Weitao; Huang, Dong; Zhang, Yan; Liu, Yangyang; Gu, Yueqing; Qian, Zhiyu

    2016-09-01

    Photodynamic therapy (PDT) is an effective noninvasive method for the tumor treatment. The major challenge in current PDT research is how to quantitatively evaluate therapy effects. To our best knowledge, this is the first time to combine multi-parameter detection methods in PDT. More specifically, we have developed a set of system, including the high-sensitivity measurement of singlet oxygen, oxygen partial pressure and fluorescence image. In this paper, the detection ability of the system was validated by the different concentrations of carbon quantum dots. Moreover, the correlation between singlet oxygen and oxygen partial pressure with laser irradiation was observed. Then, the system could detect the signal up to 0.5 cm tissue depth with 660 nm irradiation and 1 cm tissue depth with 980 nm irradiation by using up-conversion nanoparticles during PDT in vitro. Furthermore, we obtained the relationship among concentration of singlet oxygen, oxygen partial pressure and tumor cell viability under certain conditions. The results indicate that the multi-parameter detection system is a promising asset to evaluate the deep tumor therapy during PDT. Moreover, the system might be potentially used for the further study in biology and molecular imaging. PMID:26833036

  3. Clinical evaluation of contemporary oxygenators.

    Science.gov (United States)

    Stanzel, Roger D P; Henderson, Mark

    2016-01-01

    Advances in cardiopulmonary bypass equipment have played a critical role in improving outcomes for cardiac surgery patients. Recent advancements include reduced priming volumes, biocompatible coatings and gaseous microemboli handling, as well as the incorporation of an arterial filter into the oxygenator.The purpose of this study was to conduct a comprehensive clinical evaluation of adult oxygenators on the market. Oxygenators assessed included the Sorin Synthesis(®) (n = 30), the Sorin Inspire 6F(®) (n = 10) and Inspire 8F(®) (n = 30), the Terumo FX15(®) (n = 13) and FX25(®) (n = 30), the Maquet Quadrox-i(®) (n = 30) and the Medtronic Fusion(®) (n = 30). Parameters assessed included functional prime volumes, gas exchange, pressure gradients and the effects on patient hematology.The Synthesis had the largest functional prime volume (1426 ml), the FX15 the lowest (956 ml). The Inspire 6F, 8F and Fusion had the greatest O2 transfer. The Sorin oxygenators required the lowest sweep gas flows to obtain a PaCO2 of 40 mmHg. The Sorin oxygenators had the largest pressure gradients. While no differences were observed for hemoglobin and platelet levels post cross-clamp removal, the Sorin Synthesis and Inspire 8F had the largest increases in white blood cell (WBC) counts (122% and 141% of baseline, respectively) and neutrophils (162% and 185% of baseline, respectively).The data demonstrate that no single product is superior in all aspects. The choice of ideal oxygenator depends on the aspect(s) of oxygenator performance the perfusion team believes most clinically acceptable based on available data. PMID:26407816

  4. Oxygen Transport Ceramic Membranes

    Energy Technology Data Exchange (ETDEWEB)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-05-01

    been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  5. Low oxygen biomass-derived pyrolysis oils and methods for producing the same

    Science.gov (United States)

    Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

    2013-08-27

    Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

  6. Analog voltmeter for measuring oxygen concentration in fast reactor sodium circuits

    International Nuclear Information System (INIS)

    An analog voltmeter designed for oxygen concentration measurement in the sodium coolant of fast reactors and thus the determination of oxygen corrosion action on the reactor core materials was tested in a sodium loop. The oxygen concentration is determined from the measurements of voltage across a solid electrolyte galvanic cell and of ambient temperature measured by a thermocouple. Thermocouple voltage ranges within 10 and 21 mV while the input from the galvanic cell within 0.2 and 0.45 V. The measured values of both quantities are combined at the analog voltmeter output according to a certain relation shown and give oxygen concentration. (Z.M.)

  7. Oxygenation measurements in head and neck cancers during hyperbaric oxygenation

    International Nuclear Information System (INIS)

    Background: Tumor hypoxia has proven prognostic impact in head and neck cancers and is associated with poor response to radiotherapy. Hyperbaric oxygenation (HBO) offers an approach to overcome hypoxia. We have performed pO2 measurements in selected patients with head and neck cancers under HBO to determine in how far changes in the oxygenation occur and whether a possible improvement of oxygenation parameters is maintained after HBO. Patients and Methods: Seven patients (five male, two female, age 51-63 years) with squamous cell cancers of the head and neck were investigated (six primaries, one local recurrence). The median pO2 prior to HBO was determined with the Eppendorf histograph. Sites of measurement were enlarged cervical lymph nodes (n = 5), the primary tumor (n = 1) and local recurrence (n = 1). Patients then underwent HBO (100% O2 at 240 kPa for 30 minutes) and the continuous changes in the oxygenation during HBO were determined with a Licox probe. Patients had HBO for 30 minutes (n = 6) to 40 minutes (n = 1). HBO was continued because the pO2 had not reached a steady state after 30 minutes. After decompression, patients ventilated pure oxygen under normobaric conditions and the course of the pO2 was further measured over about 15 minutes. Results: Prior to HBO, the median tumor pO2 in the Eppendorf histography was 8.6 ± 5.4 mm Hg (range 3-19 mm Hg) and the pO2 measured with the Licox probe was 17.3 ± 25.5 mm Hg (range 0-73 mm Hg). The pO2 increased significantly during HBO to 550 ± 333 mm Hg (range 85-984 mm Hg, p = 0.018). All patients showed a marked increase irrespective of the oxygenation prior to HBO. The maximum pO2 in the tumor was reached after 10-33 minutes (mean 17 minutes). After leaving the hyperbaric chamber, the pO2 was 282 ± 196 mm Hg. All patients maintained an elevated pO2 for further 5-25 minutes (138 ± 128 mm Hg, range 42-334 mm Hg, p = 0.028 vs the pO2 prior to HBO). Conclusions: Hyperbaric oxygenation resulted in a significant

  8. Oxygen-Partial-Pressure Sensor for Aircraft Oxygen Mask

    Science.gov (United States)

    Kelly, Mark; Pettit, Donald

    2003-01-01

    A device that generates an alarm when the partial pressure of oxygen decreases to less than a preset level has been developed to help prevent hypoxia in a pilot or other crewmember of a military or other high-performance aircraft. Loss of oxygen partial pressure can be caused by poor fit of the mask or failure of a hose or other component of an oxygen distribution system. The deleterious physical and mental effects of hypoxia cause the loss of a military aircraft and crew every few years. The device is installed in the crewmember s oxygen mask and is powered via communication wiring already present in all such oxygen masks. The device (see figure) includes an electrochemical sensor, the output potential of which is proportional to the partial pressure of oxygen. The output of the sensor is amplified and fed to the input of a comparator circuit. A reference potential that corresponds to the amplified sensor output at the alarm oxygen-partial-pressure level is fed to the second input of the comparator. When the sensed partial pressure of oxygen falls below the minimum acceptable level, the output of the comparator goes from the low state (a few millivolts) to the high state (near the supply potential, which is typically 6.8 V for microphone power). The switching of the comparator output to the high state triggers a tactile alarm in the form of a vibration in the mask, generated by a small 1.3-Vdc pager motor spinning an eccentric mass at a rate between 8,000 and 10,000 rpm. The sensation of the mask vibrating against the crewmember s nose is very effective at alerting the crewmember, who may already be groggy from hypoxia and is immersed in an environment that is saturated with visual cues and sounds. Indeed, the sensation is one of rudeness, but such rudeness could be what is needed to stimulate the crewmember to take corrective action in a life-threatening situation.

  9. Impurities of oxygen in silicon

    International Nuclear Information System (INIS)

    The electronic structure of oxygen complex defects in silicon, using molecular cluster model with saturation by watson sphere into the formalism of Xα multiple scattering method is studied. A systematic study of the simulation of perfect silicon crystal and an analysis of the increasing of atom number in the clusters are done to choose the suitable cluster for the calculations. The divacancy in three charge states (Si:V2+, Si:V20, Si:V2-), of the oxygen pair (Si:O2) and the oxygen-vacancy pair (Si:O.V) neighbours in the silicon lattice, is studied. Distortions for the symmetry were included in the Si:V2+ and Si:O2 systems. The behavior of defect levels related to the cluster size of Si:V20 and Si:O2 systems, the insulated oxygen impurity of silicon in interstitial position (Si:Oi), and the complexes involving four oxygen atoms are analysed. (M.C.K.)

  10. A mechanistic investigation of the oxygen fixation hypothesis and oxygen enhancement ratio

    OpenAIRE

    Grimes, David Robert; Partridge, Mike

    2015-01-01

    The presence of oxygen in tumours has substantial impact on treatment outcome; relative to anoxic regions, well-oxygenated cells respond better to radiotherapy by a factor 2.5–3. This increased radio-response is known as the oxygen enhancement ratio. The oxygen effect is most commonly explained by the oxygen fixation hypothesis, which postulates that radical-induced DNA damage can be permanently ‘fixed’ by molecular oxygen, rendering DNA damage irreparable. While this oxygen effect is importa...

  11. Make Liquid Oxygen in Your Class

    Science.gov (United States)

    French, M. M. J.; Hibbert, Michael

    2010-01-01

    Oxygen is one of the component gases of air at room temperature, making up around 20% of the atmosphere. But can oxygen be liquified? This article details a method for making small amounts of liquid oxygen in the classroom if there is no access to a cylinder of compressed oxygen gas, and two methods for identifying the fact that it is liquid…

  12. 21 CFR 868.5580 - Oxygen mask.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxygen mask. 868.5580 Section 868.5580 Food and... ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5580 Oxygen mask. (a) Identification. An oxygen mask is a device placed over a patient's nose, mouth, or tracheostomy to administer oxygen or aerosols. (b)...

  13. 49 CFR 172.530 - OXYGEN placard.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false OXYGEN placard. 172.530 Section 172.530... SECURITY PLANS Placarding § 172.530 OXYGEN placard. (a) Except for size and color, the OXYGEN placard must... background color on the OXYGEN placard must be yellow. The symbol, text, class number and inner border...

  14. 46 CFR 197.326 - Oxygen safety.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Oxygen safety. 197.326 Section 197.326 Shipping COAST... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.326 Oxygen safety. (a) Equipment used with oxygen or oxygen mixtures greater than 40 percent by volume must be designed for such use. (b)...

  15. Comparison of pulse sequences for R1-based electron paramagnetic resonance oxygen imaging

    Science.gov (United States)

    Epel, Boris; Halpern, Howard J.

    2015-05-01

    Electron paramagnetic resonance (EPR) spin-lattice relaxation (SLR) oxygen imaging has proven to be an indispensable tool for assessing oxygen partial pressure in live animals. EPR oxygen images show remarkable oxygen accuracy when combined with high precision and spatial resolution. Developing more effective means for obtaining SLR rates is of great practical, biological and medical importance. In this work we compared different pulse EPR imaging protocols and pulse sequences to establish advantages and areas of applicability for each method. Tests were performed using phantoms containing spin probes with oxygen concentrations relevant to in vivo oxymetry. We have found that for small animal size objects the inversion recovery sequence combined with the filtered backprojection reconstruction method delivers the best accuracy and precision. For large animals, in which large radio frequency energy deposition might be critical, free induction decay and three pulse stimulated echo sequences might find better practical usage.

  16. Nanoparticulate-catalyzed oxygen transfer processes

    Science.gov (United States)

    Hunt, Andrew T.; Breitkopf, Richard C.

    2009-12-01

    Nanoparticulates of oxygen transfer materials that are oxides of rare earth metals, combinations of rare earth metals, and combinations of transition metals and rare earth metals are used as catalysts in a variety of processes. Unexpectedly large thermal efficiencies are achieved relative to micron sized particulates. Processes that use these catalysts are exemplified in a multistage reactor. The exemplified reactor cracks C6 to C20 hydrocarbons, desulfurizes the hydrocarbon stream and reforms the hydrocarbons in the stream to produce hydrogen. In a first reactor stage the steam and hydrocarbon are passed through particulate mixed rare earth metal oxide to crack larger hydrocarbon molecules. In a second stage, the steam and hydrocarbon are passed through particulate material that desulfurizes the hydrocarbon. In a third stage, the hydrocarbon and steam are passed through a heated, mixed transition metal/rare earth metal oxide to reform the lower hydrocarbons and thereby produce hydrogen. Stages can be alone or combined. Parallel reactors can provide continuous reactant flow. Each of the processes can be carried out individually.

  17. Evaluation of different oxygen, carbon dioxide and nitrogen combinations employed to extend the shelf life of fresh-cut collard greens Avaliação de diferentes combinações de oxigênio, gás carbônico e nitrogênio utilizadas no aumento de vida de prateleira de couve minimamente processada

    Directory of Open Access Journals (Sweden)

    Celso L. Moretti

    2003-12-01

    Full Text Available Collard greens (Brassica oleracea var. acephala "Manteiga" were harvested in commercial fields in Brasilia, Brazil, aiming to evaluate different oxygen, carbon dioxide and nitrogen combinations to extend the shelf life of the fresh-cut product. After harvest, leaves were taken to the postharvest laboratory, selected for external blemishes and minimally processed (3 mm thick inside a cold room (13±2°C. After processing, fresh-cut collard greens were stored under two controlled atmosphere (CA conditions (3% O2, 4% CO2; 5% O2, 5% CO2/balance N2, and normal air (control, at 5°C (95±2% RH, for six days. Daily, minimally processed collard greens were evaluated for total vitamin C, total chlorophyll, total soluble solids content, and titratable acidity. Total vitamin C content decreased for all treatments during the storage period. Storage under CA conditions delayed total vitamin C degradation for both atmospheres studied. At the end of the storage period, fresh-cut collard greens stored under 3% O2, 4% CO2 showed around 25% and 56% more vitamin C than the material stored under 5% O2, 5% CO2 and control, respectively. Total chlorophyll content decreased during the storage period. At the end of the experiment, fresh-cut collard greens stored under 3% O2, 4% CO2 showed 24% and 45% more total chlorophyll than the product stored under 5% O2, 5% CO2 and control, respectively. CA storage delayed organic acid degradation. On the sixth day, fresh-cut collard greens stored under 3% O2, 4% CO2 presented around 44% more organic acids than control. Total soluble solids content were not significantly affected.Folhas de couve (Brassica oleracea var. acephala "Manteiga" foram obtidas em campos de produção comercial em Brasília, DF, com o objetivo de avaliar diferentes combinações de oxigênio, dióxido de carbono e nitrogênio para estender a vida de prateleira do produto minimamente processado. Após colhidas, as folhas foram levadas ao laboratório de p

  18. A combined biological-chemical approach supported by granulated iron and methanol for nitrate removal from oxygen rich groundwater%粒状铁与甲醇支持的生物-化学联用法去除富氧地下水中硝酸盐

    Institute of Scientific and Technical Information of China (English)

    黄国鑫; H.FALLOWFIELD; H.GUAN; 刘菲

    2012-01-01

    According to the target contaminant-nitrate (NO3) in oxygen rich groundwater, a combined biological-chemical approach supported by granulated iron and methanol was put forward. Batch tests were conducted to optimize denitrification reaction parameters, and preliminarily explode the capacities and pathways of deoxygenation and denitrification. The results indicated, the optimal parameters, i.e., granulated iron type of Gl-Beijing, granulated iron: water ratio of 3: 800 (in weight), granulated iron particle size of 0.425~1.0 mm, reaction time of 5 day, methanol mass concentration of 210.59 mg·L-1, were identified. 174 min, 206 min and 2746 min were needed to completely remove DO for the biological-chemical approach, granulated iron and aerobic heterotrophic bacteria, respectively. The deoxygenation of the approach depended on granulated iron-based chemical reduction and aerobic heterotrophic bacteria-based aerobic respiration, and the former played a key role. With increasing reaction time, NO3 percent removal by respective heterotrophic denitrification (HD), autotrophic denitrification (AD) and chemical reduction (CR) increased. The percent removal efficiencies by AD and CR were lower than 10% at reaction time < 5 days, whereas the corresponding value by the approach was close to 100% at reaction time of 5 days. The biological-chemical approach relied on 3 denitrification pathways-HD, AD and CR, and HD was the most important pathway. There existed symbiotic, synergistic and promotive effects of CR, HD and AD within the system of the approach. Nitrate reduction rate was greater than (or equal to) nitrite reduction rate during denitrification by the approach. It's feasible and effective for the biological-chemical approach to remove nitrate from groundwater.%针对富氧地下水中硝酸盐,采用粒状铁和甲醇支持的生物-化学联用法开展了批实验研究,优化了脱氮反应参数,初步探讨了脱氧脱氮的能力及途径.结果表明,该法

  19. Cerebral oxygenation is reduced during hyperthermic exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, P.; Nybo, Lars; Volianitis, Stefanos; Møller, K.; Secher, N. H.; Gjedde, A.

    2010-01-01

    reduced by 15 +/- 13% (P < 0.05). During exercise with heat stress, RPE increased to 19 (19-20; P < 0.05); the RPE correlated inversely with P(mito)O(2) (r(2) = 0.42, P < 0.05). Conclusion: These data indicate that strenuous exercise in the heat lowers cerebral P(mito)O(2), and that exercise capacity in......Abstract Aim: Cerebral mitochondrial oxygen tension (P(mito)O(2)) is elevated during moderate exercise, while it is reduced when exercise becomes strenuous, reflecting an elevated cerebral metabolic rate for oxygen (CMRO(2)) combined with hyperventilation-induced attenuation of cerebral blood flow...... (CBF). Heat stress challenges exercise capacity as expressed by increased rating of perceived exertion (RPE). Methods: This study evaluated the effect of heat stress during exercise on P(mito)O(2) calculated based on a Kety-Schmidt-determined CBF and the arterial-to-jugular venous oxygen differences in...

  20. Electrochemical determination of oxygen stoichiometry and entropy in oxides

    DEFF Research Database (Denmark)

    Zachau-Christiansen, Birgit; Jacobsen, Torben; Skaarup, Steen

    The oxygen stoichiometry of CeO2 and Ce0.82Gd0.18O1.91 is determined by a combination of cyclic voltammetry and coulometric titration. The electrochemical cell employed is an oxygen pumping cell, in which the oxide is subjected to different oxygen pressures corresponding to the potential imposed in...... the temperature range 800-1000 degrees C. With scan rates of 2 mu V/s potential sweeps on CeO2 are reversible. The change in entropy is determined by either subtraction of e.m.f. curves obtained by potential sweeps of different temperatures or by measuring the e.m.f. during a temperature scan. The...... latter method yields the most reliable results. Potential sweeps on Ce0.8Ca0.2O1.8 suggest that calcium is expelled from the lattice....

  1. MR Imaging-derived Oxygen-Hemoglobin Dissociation Curves and Fetal-Placental Oxygen-Hemoglobin Affinities.

    Science.gov (United States)

    Avni, Reut; Golani, Ofra; Akselrod-Ballin, Ayelet; Cohen, Yonni; Biton, Inbal; Garbow, Joel R; Neeman, Michal

    2016-07-01

    Purpose To generate magnetic resonance (MR) imaging-derived, oxygen-hemoglobin dissociation curves and to map fetal-placental oxygen-hemoglobin affinity in pregnant mice noninvasively by combining blood oxygen level-dependent (BOLD) T2* and oxygen-weighted T1 contrast mechanisms under different respiration challenges. Materials and Methods All procedures were approved by the Weizmann Institutional Animal Care and Use Committee. Pregnant mice were analyzed with MR imaging at 9.4 T on embryonic days 14.5 (eight dams and 58 fetuses; imprinting control region ICR strain) and 17.5 (21 dams and 158 fetuses) under respiration challenges ranging from hyperoxia to hypoxia (10 levels of oxygenation, 100%-10%; total imaging time, 100 minutes). A shorter protocol with normoxia to hyperoxia was also performed (five levels of oxygenation, 20%-100%; total imaging time, 60 minutes). Fast spin-echo anatomic images were obtained, followed by sequential acquisition of three-dimensional gradient-echo T2*- and T1-weighted images. Automated registration was applied to align regions of interest of the entire placenta, fetal liver, and maternal liver. Results were compared by using a two-tailed unpaired Student t test. R1 and R2* values were derived for each tissue. MR imaging-based oxygen-hemoglobin dissociation curves were constructed by nonlinear least square fitting of 1 minus the change in R2*divided by R2*at baseline as a function of R1 to a sigmoid-shaped curve. The apparent P50 (oxygen tension at which hemoglobin is 50% saturated) value was derived from the curves, calculated as the R1 scaled value (x) at which the change in R2* divided by R2*at baseline scaled (y) equals 0.5. Results The apparent P50 values were significantly lower in fetal liver than in maternal liver for both gestation stages (day 14.5: 21% ± 5 [P = .04] and day 17.5: 41% ± 7 [P MR imaging-based oxygen-hemoglobin dissociation curves with a shorter protocol that excluded the hypoxic periods was demonstrated

  2. Defective titanium dioxide single crystals exposed by high-energy {001} facets for efficient oxygen reduction

    Science.gov (United States)

    Pei, Dan-Ni; Gong, Li; Zhang, Ai-Yong; Zhang, Xing; Chen, Jie-Jie; Mu, Yang; Yu, Han-Qing

    2015-10-01

    The cathodic material plays an essential role in oxygen reduction reaction for energy conversion and storage systems. Titanium dioxide, as a semiconductor material, is usually not recognized as an efficient oxygen reduction electrocatalyst owning to its low conductivity and poor reactivity. Here we demonstrate that nano-structured titanium dioxide, self-doped by oxygen vacancies and selectively exposed with the high-energy {001} facets, exhibits a surprisingly competitive oxygen reduction activity, excellent durability and superior tolerance to methanol. Combining the electrochemical tests with density-functional calculations, we elucidate the defect-centred oxygen reduction reaction mechanism for the superiority of the reductive {001}-TiO2-x nanocrystals. Our findings may provide an opportunity to develop a simple, efficient, cost-effective and promising catalyst for oxygen reduction reaction in energy conversion and storage technologies.

  3. Effect of hyperbaric oxygen conditions on the ordering of interfacial water.

    Science.gov (United States)

    Ypma, Rolf E; Pollack, Gerald H

    2015-01-01

    Hyperbaric oxygen (HBO2) conditions are applied clinically to treat diverse conditions. There is a lack of a unifying consensus as to how HBO2 acts effectively against a broad range of medical conditions, and numerous differing biological explanations have been offered. The possibility of a mechanism dependent on the extensive ordering of interfacial water has not yet been investigated. We examined the hypothesis that zones of ordered water, dubbed "exclusion zones" or "EZ," are expanded under hyperbaric oxygen conditions. Specifically, we tested whether there are significant quantitative differences in EZ size at steady state under high-pressure and/or high-oxygen conditions, compared to normal atmospheric conditions. Oxygen concentration and mechanical pressure were examined separately and in combination. Statistically significant increases in EZ size were seen at elevated air pressures and at high oxygen concentrations. These experimental results suggest the possibility of an ordered water-mediated mechanism of action for hyperbaric oxygen therapy. PMID:26152107

  4. Development of a Supersonic Atomic Oxygen Nozzle Beam Source for Crossed Beam Scattering Experiments

    Science.gov (United States)

    Sibener, S. J.; Buss, R. J.; Lee, Y. T.

    1978-05-01

    A high pressure, supersonic, radio frequency discharge nozzle beam source was developed for the production of intense beams of ground state oxygen atoms. An efficient impedance matching scheme was devised for coupling the radio frequency power to the plasma as a function of both gas pressure and composition. Techniques for localizing the discharge directly behind the orifice of a water-cooled quartz nozzle were also developed. The above combine to yield an atomic oxygen beam source which produces high molecular dissociation in oxygen seeded rare gas mixtures at total pressures up to 200 torr: 80 to 90% dissociation for oxygen/argon mixtures and 60 to 70% for oxygen/helium mixtures. Atomic oxygen intensities are found to be greater than 10{sup 17} atom sr{sup -1} sec{sup -1}. A brief discussion of the reaction dynamics of 0 + IC1 ..-->.. I0 + C1 is also presented.

  5. Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba

    DEFF Research Database (Denmark)

    Hoffmann, F.; Røy, Hans; Bayer, K.;

    2008-01-01

    The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba...... specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive...... flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges...

  6. Metabolism of oxygen during photorespiration

    International Nuclear Information System (INIS)

    18O2 was used to determine the simultaneous uptake and release of oxygen by leaf fragments and algae suspensions during photosynthesis. The rate of uptake was strongly dependent on the relative concentrations of O2 and CO2, but also on the light intensity. Millimolar cyanide inhibited CO2 fixation but did not change significantly the O2 uptake observed at the CO2 compensation point, suggesting that O2 can act as an acceptor of the photosynthetically generated reducing power. If hydrogen peroxide is the reduced species of oxygen produced under light, H2O2 elimination can proceed via peroxidation of keto-compounds

  7. The oxygen minimum of the Elbe river

    International Nuclear Information System (INIS)

    Several longitudinal profiles for oxygen have been recorded in connection with the reduced oxygen content of the Elbe river in June 1979. Apart from conventional methods of measurement, e.g. titration of water samples and in-situ measurements in stations with oxygen probes, also continuous recordings of the oxygen content of the Elbe water were made aboard the MONITOR measuring vessel. The recorded oxygen distributions are discussed as well as selected heavy metal and nutrient concentrations. (orig.)

  8. Influence of plasma chemistry on oxygen triplets

    OpenAIRE

    Milosavljevic, Vladimir; Ellingboe, Albert; Daniels, Stephen

    2011-01-01

    The plasma chemistry of fluorocarbon-oxygen-argon discharges and its influence on prominent oxygen triplets are studied. The oxygen 777 triplet is very important for the measurement of atomic oxygen in low pressure plasmas, since the 777.417 nm spectral line is frequently used for actinometry. In this paper we identify changes in the individual 777 triplet lines arising from cascade effects from higher energy levels of oxygen, and from resonant energy transfer from energetic carbon...

  9. Type of Mask May Impact on Continuous Positive Airway Pressure Adherence in Apneic Patients

    OpenAIRE

    Borel, Jean Christian; Tamisier, Renaud; Dias-Domingos, Sonia; Sapene, Marc; Martin, Francis; Stach, Bruno; Grillet, Yves; Muir, Jean François; Levy, Patrick; Series, Frederic; Pepin, Jean-Louis; ,

    2013-01-01

    Rationale In obstructive sleep apnea patients (OSA), continuous positive airway pressure (CPAP) adherence is crucial to improve symptoms and cardiometabolic outcomes. The choice of mask may influence CPAP adherence but this issue has never been addressed properly. Objective To evaluate the impact of nasal pillows, nasal and oronasal masks on CPAP adherence in a cohort of OSA. Methods Newly CPAP treated OSA participating in “Observatoire Sommeil de la Fédération de Pneumologie”, a French natio...

  10. A test for evaluation of exercise with apneic episodes in synchronized swimming.

    Science.gov (United States)

    Naranjo, J; Centeno, R A; Carranza, M D; Cayetano, M

    2006-12-01

    In synchronized swimming, complex maneuvers are developed in the water alternating air breathing and apnea episodes, which activate complex and adjusted mechanisms for respiratory compensation. The aim of this study is to propose a specific laboratory test for the assessment of the functional respiratory adaptations during exercise with apnea periods in synchronized swimmers. We studied 25 women, of which 13 were elite synchronized swimmers and the other 12 were a control group. A laboratory test was performed on a cycle ergometer consisting of 4 minutes pedalling at a constant intensity of 1.5 watts/kg (test 1). After 30 minutes at rest, a new test was performed alternating free respiration and apnea periods of 15 seconds at the same intensity (test 2). In both tests HR, VE, VT, BF, VO2, VCO2, and lactate were analyzed. We observed an increase in VE, VO2, and VCO2 in the 13 swimmers in test 2, with no change in HR and lactate, and a constant relationship between VE and VCO2 equal for tests 1 and 2. In the control group only 6 women completed test 2, the other 6 stopped before the third minute. In this group, important differences were observed in relation to the swimmers: both heart rate and lactate increased in test 2 and showed an increase in the VE vs. VCO2 relationship which involved a different slope for test 1 and test 2. We conclude that functional respiratory adaptations induced by apnea during synchronized swimming are essential in this sport and the test proposed may be a useful tool to assess the physical performance in synchronized swimmers. PMID:17024622

  11. Novel Molten Oxide Membrane for Ultrahigh Purity Oxygen Separation from Air.

    Science.gov (United States)

    Belousov, Valery V; Kulbakin, Igor V; Fedorov, Sergey V; Klimashin, Anton A

    2016-08-31

    We present a novel solid/liquid Co3O4-36 wt % Bi2O3 composite that can be used as molten oxide membrane, MOM ( Belousov, V. V. Electrical and Mass Transport Processes in Molten Oxide Membranes. Ionics 22 , 2016 , 451 - 469 ), for ultrahigh purity oxygen separation from air. This membrane material consists of Co3O4 solid grains and intergranular liquid channels (mainly molten Bi2O3). The solid grains conduct electrons, and the intergranular liquid channels predominantly conduct oxygen ions. The liquid channels also provide the membrane material gas tightness and ductility. This last property allows us to deal successfully with the problem of thermal incompatibility. Oxygen and nitrogen permeation fluxes, oxygen ion transport number, and conductivity of the composite were measured by the gas flow, volumetric measurements of the faradaic efficiency, and four-probe dc techniques, accordingly. The membrane material showed the highest oxygen selectivity jO2/jN2 > 10(5) and sufficient oxygen permeability 2.5 × 10(-8) mol cm(-1) s(-1) at 850 °C. In the range of membrane thicknesses 1.5-3.3 mm, the oxygen permeation rate was controlled by chemical diffusion. The ease of the MOM fabrication, combined with superior oxygen selectivity and competitive oxygen permeability, shows the promise of the membrane material for ultrahigh purity oxygen separation from air. PMID:27482771

  12. Measuring Spatial and Temporal Heterogeneity of Dissolved Oxygen in Streambed Sediments Using Pressure Sensitive Paint (PSP)

    Science.gov (United States)

    Huynh, K. T.; Salus, A.; Xie, M.; Roche, K. R.; Packman, A. I.

    2014-12-01

    Pressure sensitive paints (PSP) have been largely used in aerodynamic applications to measure pressure distributions on complex bodies such as aircraft. One common family of PSPs employ fluorescent pigments that are quenched in the presence of oxygen, yielding an inverse relationship between fluorescence intensity and oxygen concentration that is used to measure pressure in aerodynamic applications through the partial pressure of oxygen. These PSPs offer unexplored potential for visualizing dissolved oxygen (DO) concentration distributions on surfaces underwater. PSP was used to measure dissolved oxygen concentrations in streambed sediments in a laboratory flume. Two PSP-coated 2.5 cm diameter spheres were emplaced in a bed of similar material, and imaged under varying DO concentrations. Calibration curves relating fluorescence intensity to dissolved oxygen concentration were developed on a pixel-by-pixel basis, enabling spatial patterns of oxygen to be resolved in the sediment bed. This method of measuring dissolved oxygen concentration is advantageous because of its fast response time and ability to measure heterogeneous oxygen distributions in sediments. Future work will explore the combined effects of stream flow and biofilm growth on oxygen distributions in streambed sediments.

  13. Applications of quantum dots in optical fiber luminescent oxygen sensors

    Science.gov (United States)

    Jorge, Pedro A. S.; Mayeh, Mona; Benrashid, Ramazan; Caldas, Paulo; Santos, José L.; Farahi, Faramarz

    2006-06-01

    The potential applications of luminescent semiconductor nanocrystals to optical oxygen sensing are explored. The suitability of quantum dots to provide a reference signal in luminescence-based chemical sensors is addressed. A CdSe-ZnS nanocrystal, with an emission peak at 520 nm, is used to provide a reference signal. Measurements of oxygen concentration, which are based on the dynamic quenching of the luminescence of a ruthenium complex, are performed. Both the dye and the nanocrystal are immobilized in a solgel matrix and are excited by a blue LED. Experimental results show that the ratio between the reference and the sensor signals is highly insensitive to fluctuations of the excitation optical power. The use of CdTe, near-infrared quantum dots with an emission wavelength of 680 nm, in combination with a ruthenium complex to provide a new mechanism for oxygen sensing, is investigated. The possibility of creating oxygen sensitivity in different spectral regions is demonstrated. The results obtained clearly show that this technique can be applied to develop a wavelength division multiplexed system of oxygen sensors.

  14. Oxygen diffusion through soil covers on sulphidic mine tailings

    International Nuclear Information System (INIS)

    Engineered soil covers are being evaluated under Canada's Mine Environment Neutral Drainage (MEND) program for their effectiveness in preventing and controlling acid generation in sulfidic mill tailings. A critical parameter for predicting the performance of these covers is the diffusion coefficient of gaseous oxygen in the cover materials. Laboratory experiments conducted to determine the effective diffusion coefficient of a candidate cover material, a glacial till from an active mine site, are described. The diffusion coefficient is determined by fitting a semianalytic solution of the one-dimensional, transient diffusion equation to experimental gaseous oxygen concentration versus time graphs. Effective diffusion coefficients determined at high water saturations (85%--95%) were of the order of 8 x 10-8 m2/s. The diffusion coefficients decreased with increase in water saturation as a result of the low diffusivity of gaseous oxygen in water relative to that in air and the low solubility of oxygen in water. Placement of soil covers in high saturation conditions would ensure that the flux of oxygen into tailings underneath such covers is low, resulting in low acid flux. This is confirmed by combined laboratory, field, and modeling studies

  15. Chemically active species in an Oxygen Inductively Coupled Plasma

    Science.gov (United States)

    Ly, Nathaniel; Boffard, John; Lin, Chun; Wendt, Amy; Radovanov, Svetlana; Persing, Harold; Likhanskii, Alexandre

    2015-09-01

    Oxygen plasmas are used in a wide variety of applications including ion implantation and photoresist striping. Here we combine noninvasive optical emission spectroscopy (OES) measurements and numerical simulations to investigate the plasma parameters in both oxygen inductively coupled plasmas (ICP) and oxygen-argon ICPs. An emission model makes use of available electron impact excitation cross sections for atomic and molecular oxygen to relate measured O and O2+emission intensities to corresponding plasma parameters, including the electron temperature, electron density, and the dissociation fraction of the neutral oxygen. For plasma simulations we use the CRTRS, 2D/3D code that selfconsistently solves for ICP power deposition, electrostatic potential and plasma dynamics in the driftdiffusion approximation (or full momentum equations). Comparison of the experimental OES measurements are used to check the validity of the plasma simulation which yields results that the OES approach has difficulty in measuring including the relative fluxes of O+ and O2+,which is important for ion implantation. The authors acknowledge support from NSF Grant PHY-1068670, and from Dr. Shahid Rauf for developing CRTRS.

  16. Self-sufficient and exclusive oxygenation of methane and its source materials with oxygen to methanol via metgas using oxidative bi-reforming.

    Science.gov (United States)

    Olah, George A; Prakash, G K Surya; Goeppert, Alain; Czaun, Miklos; Mathew, Thomas

    2013-07-10

    A combination of complete methane combustion with oxygen of the air coupled with bi-reforming leads to the production of metgas (H2/CO in 2:1 mole ratio) for exclusive methanol synthesis. The newly developed oxidative bi-reforming allows direct oxygenation of methane to methanol in an overall economic and energetically efficient process, leaving very little, if any, carbon footprint or byproducts. PMID:23795911

  17. Synthesis gas production using oxygen storage materials as oxygen carrier over circulating fluidized bed

    Institute of Scientific and Technical Information of China (English)

    DAI Xiaoping; YU Changchun; LI Ranjia; WU Qiong; HAO Zhengping

    2008-01-01

    A novel process for synthesis gas production over Circulating Fluidized Bed (CFB) using oxygen storage materials as oxygen carrier was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9Co0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.

  18. Oxygen supply and consumption in soilless culture: evaluation of an oxygen simulation model for cucumber

    NARCIS (Netherlands)

    Baas, R.; Wever, G.; Koolen, A.J.; Tariku, E.; Stol, K.J.

    2001-01-01

    A soil oxygen simulation model (OXSI) was tested and evaluated for evaluating growing media with respect to aeration. In the model, local oxygen concentrations are calculated from coefficients of diffusion and consumption (respiration), assuming equilibrium conditions. Apparent oxygen diffusion coef

  19. Oxygen intake in ion irradiated fullerene films

    International Nuclear Information System (INIS)

    The present work reports the change in the oxygen content in energetic ion irradiated fullerene films. The oxygen contents in irradiated films have been studied using on-line elastic recoil detection analysis (ERDA) and off-line X-ray photo electron emission (XPS) and nuclear reaction analysis (NRA) techniques. The XPS and NRA techniques show that the oxygen content increases with ion fluence, whereas on-line ERDA measurements reveal that the oxygen content decreases with ion fluence. These experiments give clear evidence that oxygen content in irradiated films increases after exposure to the atmospheric oxygen

  20. Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation

    OpenAIRE

    Wang Jiun; Dharmakumar Rohan; Green Jordin D; Flewitt Jacqueline A; Vöhringer Matthias; Tyberg John V; Friedrich Matthias G

    2010-01-01

    Abstract Background As myocardial oxygenation may serve as a marker for ischemia and microvascular dysfunction, it could be clinically useful to have a non-invasive measure of changes in myocardial oxygenation. However, the impact of induced blood flow changes on oxygenation is not well understood. We used oxygenation-sensitive CMR to assess the relations between myocardial oxygenation and coronary sinus blood oxygen saturation (SvO2) and coronary blood flow in a dog model in which hyperemia ...

  1. Diurnal fluctuations in root oxygen release rate and dissolved oxygen budget in wetland mesocosm

    OpenAIRE

    DONG, C.; Zhu, W; Y. Q. ZHAO; Gao, M.

    2011-01-01

    To assess the role of plants for oxygen offering in constructed wetlands, this study experimentally evaluated the amount of root oxygen release rate using mass balance method. The mass balance calculation is based on the following components: respiratory oxygen consumption of the roots; oxygen required for degradation of the organic matters; oxygen required for nitrification; and the amount of dissolved oxygen in the influent, effluent and substrate water. Experimental results have demonstrat...

  2. Diapycnal oxygen supply to the tropical North Atlantic oxygen minimum zone

    OpenAIRE

    Fischer, T; D. Banyte; Brandt, P.; Dengler, M.; Krahmann, G.; Tanhua, T.; Visbeck, M.

    2013-01-01

    The replenishment of consumed oxygen in the open ocean oxygen minimum zone (OMZ) off northwest Africa is accomplished by oxygen transport across and along density surfaces, i.e. diapycnal and isopycnal oxygen supply. Here the diapycnal oxygen supply is investigated using a large observational set of oxygen profiles and diapycnal mixing data from years 2008 to 2010. Diapycnal mixing is inferred from different sources: (i) a large-scale tracer release experiment, (ii) microstructure profiles, a...

  3. beta. -diketones containing oxygen atom in fluorinated radical

    Energy Technology Data Exchange (ETDEWEB)

    Shivanyuk, A.F.; Kudryavtseva, L.S.; Lozinskij, M.O.; Neplyuev, V.M.; Fialkov, Yu.A.; Bratolyubova, A.G. (AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    1981-10-01

    The synthesis of a number of new aliphatic fluorinated ..beta..-diketones containing oxygen atom in fluorinated radical of linear or cyclic structure is described. The reaction of combination with aryldiazonium salts resulting in the formation of corresponding arylhydrazones of fluorinated triketones is studied. It is shown that as a result of arylhydrazone condensation with hydroxylamine, hydrazine and its substituted derivatives the fluorine-containing derivatives of isoxazol and pyrazol are formed.

  4. Synthesis and characterization of gallium-based perovskite- type dense membrane with oxygen semipermeability

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    La0.15Sr0.85Ga0.3Fe0.7O3-d (LSGFO) and La0.15Sr0.85Co0.3Fe0.7O3-d (LSCFO) mixed oxygen-ion and electron conducting oxides were synthesized by using a combined EDTA and citrate complexing method, and the corresponding dense membranes were fabricated. The properties of the oxide powders and membranes were characterized with combined SEM, XRD, H2-TPR, O2-TPD techniques, mechanical strength and oxygen permeation measurement. The results showed that LSGFO had much higher thermochemical stability than LSCFO due to the higher valence stability of Ga3+. After the temperature-programmed reduction by 5% H2 in Ar from 20℃ to 1020℃, the basic perovskite structure of LSGFO was successfully preserved. LSGFO also favors the oxygen vacancy formation better than LSCFO. Oxygen permeation measurement demonstrated that LSGFO had higher oxygen permeation flux than LSCFO, but they had similar activation energy for oxygen transportation, with a value of 110 and 117 kJ omol-1, respectively. The difference in oxygen permeation fluxes was correlated with the difference in oxygen vacancy concentrations for the two materials.

  5. Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process

    Energy Technology Data Exchange (ETDEWEB)

    Ellett, Anna Judith

    2009-07-01

    The reduction of CO{sub 2} emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO{sub 2} Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global carbon mitigation effort. The oxyfuel process, which consists in the burning of coal in an oxygen-rich atmosphere to produce a flue gas highly concentrated in CO{sub 2}, is a technology considered for zero CO{sub 2} emission coal-fired power plants. The production of this O{sub 2}-rich combustion gas from air can be carried out using high purity oxygen separation membranes. Some of the most promising materials for this application are mixed ionic-electronic conducting (MIEC) materials with perovskite and K{sub 2}NiF{sub 4} perovskite-related structures. The present work examines the selection of La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58), La{sub 2}NiO{sub 4+{delta}}, Pr{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (PSCF58) and Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF50) as membrane materials for the separation of O{sub 2} and N{sub 2} in the framework of the oxyfuel process with flue gas recycling. Annealing experiments were carried out on pellets exposed to CO{sub 2}, water vapour, O{sub 2} and Cr{sub 2}O{sub 3} in order to determine the thermo-chemical resistance to the atmospheres and the high temperature conditions present during membrane operation in a coal-fired power plant. The degradation of their microstructure was investigated using Scanning Electron Microscopy (SEM) in combination with electron dispersive spectroscopy (EDS) as well as X-Ray Diffraction (XRD). Also, the oxygen permeation fluxes of selected membranes were investigated as a function of temperature. The membrane materials selected were characterised using thermo-analytical techniques such as precision thermogravimetric

  6. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  7. Adjunctive Hyperbaric Oxygen Therapy or Alone Antibiotherapy? Methicillin Resistant Staphylococcus aureus Mediastinitis in a Rat Model

    Directory of Open Access Journals (Sweden)

    Tolga Kurt

    2015-10-01

    Full Text Available ABSTRACT OBJECTIVE: In the post-sternotomy mediastinitis patients, Staphylococcus aureus is the pathogenic microorganism encountered most often. In our study, we aimed to determine the efficacy of antibiotic treatment with vancomycin and tigecycline, alone or in combination with hyperbaric oxygen treatment, on bacterial elimination in experimental S. aureus mediastinitis. METHODS: Forty-nine adult female Wistar rats were used. They were randomly divided into seven groups, as follows: non-contaminated, contaminated control, vancomycin, tigecycline, hyperbaric oxygen, hyperbaric oxygen + vancomycin and hyperbaric oxygen + tigecycline. The vancomycin rat group received 10 mg/kg/day of vancomycin twice a day through intramuscular injection. The tigecycline group rats received 7 mg/kg/day of tigecycline twice a day through intraperitoneal injection. The hyperbaric oxygen group underwent 90 min sessions of 100% oxygen at 2.5 atm pressure. Treatment continued for 7 days. Twelve hours after the end of treatment, tissue samples were obtained from the upper part of the sternum for bacterial count assessment. RESULTS: When the quantitative bacterial counts of the untreated contaminated group were compared with those of the treated groups, a significant decrease was observed. However, comparing the antibiotic groups with the same antibiotic combined with hyperbaric oxygen, there was a significant reduction in microorganisms identified (P<0.05. Comparing hyperbaric oxygen used alone with the vancomycin and tigecycline groups, it was seen that the effect was not significant (P<0.05. CONCLUSION: We believe that the combination of hyperbaric oxygen with antibiotics had a significant effect on mediastinitis resulting from methicillin-resistant Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus mediastinitis can be treated without requiring a multidrug combination, thereby reducing the medication dose and concomitantly decreasing the side effects.

  8. Kinetic bottlenecks to chemical exchange rates for deep-sea animals – Part 1: Oxygen

    Directory of Open Access Journals (Sweden)

    E. T. Peltzer

    2012-10-01

    Full Text Available Ocean warming will reduce dissolved oxygen concentrations which can pose challenges to marine life. Oxygen limits are traditionally reported simply as a static concentration thresholds with no temperature, pressure or flow rate dependency. Here we treat the oceanic oxygen supply potential for heterotrophic consumption as a dynamic molecular exchange problem analogous to familiar gas exchange processes at the sea surface. A combination of the purely physico-chemical oceanic properties temperature, hydrostatic pressure, and oxygen concentration defines the ability of the ocean to supply oxygen to any given animal. This general oceanic oxygen supply potential is modulated by animal specific properties such as the diffusive boundary layer thickness to define and limit maximal oxygen supply rates. Here we combine all these properties into formal, mechanistic equations defining novel oceanic properties that subsume various relevant classical oceanographic parameters to better visualize, map, comprehend, and predict the impact of ocean deoxygenation on aerobic life. By explicitly including temperature and hydrostatic pressure into our quantities, various ocean regions ranging from the cold deep-sea to warm, coastal seas can be compared. We define purely physico-chemical quantities to describe the oceanic oxygen supply potential, but also quantities that contain organism-specific properties which in a most generalized way describe general concepts and dependencies. We apply these novel quantities to example oceanic profiles around the world and find that temperature and pressure dependencies of diffusion and partial pressure create zones of greatest physical constriction on oxygen supply typically at around 1000 m depth, which coincides with oxygen concentration minimum zones. In these zones, which comprise the bulk of the world ocean, ocean warming and deoxygenation have a clear negative effect for aerobic life. In some shallow and warm waters the

  9. Susceptibility weighted imaging of stroke brain in response to normobaric oxygen (NBO) therapy

    Science.gov (United States)

    Zhou, Iris Y.; Igarashi, Takahiro; Guo, Yingkun; Sun, Phillip Z.

    2015-03-01

    The neuroprotective effect of oxygen leads to recent interest in normobaric oxygen (NBO) therapy after acute ischemic stroke. However, the mechanism remains unclear and inconsistent outcomes were reported in human studies. Because NBO aims to improve brain tissue oxygenation by enhancing oxygen delivery to ischemic tissue, monitoring the oxygenation level changes in response to NBO becomes necessary to elucidate the mechanism and to assess the efficacy. Susceptibility weighted imaging (SWI) which provides a new MRI contrast by combining the magnitude and phase images is fit for purpose. SWI is sensitive to deoxyhemoglobin level changes and thus can be used to evaluate the cerebral metabolic rate of oxygen. In this study, SWI was used for in vivo monitoring of oxygenation changes in a rat model of permanent middle cerebral artery occlusion (MCAO) before, during and after 30 min of NBO treatment. Regions of interest in ischemic core, penumbra and contralateral normal area were generated based on diffusionweighted imaging and perfusion imaging. Significant differences in SWI indicating different oxygenation levels were generally found: contralateral normal > penumbra > ischemic core. Ischemic core showed insignificant increase in oxygenation during NBO and returned to pre-treatment level after termination of NBO. Meanwhile, the oxygenation levels slightly increased in contralateral normal and penumbra regions during NBO and significantly decreased to a level lower than pre-treatment after termination of NBO, indicating secondary metabolic disruption upon the termination of transient metabolic support from oxygen. Further investigation of NBO effect combined with reperfusion is necessary while SWI can be used to detect hemorrhagic transformation after reperfusion.

  10. Analysis of factors which affect the relationship between inspired oxygen partial pressure and arterial oxygen saturation.

    Science.gov (United States)

    Roe, P G; Jones, J G

    1993-10-01

    The adoption of pulse oximetry in anaesthesia and intensive care has resulted in oxyhaemoglobin saturation (SaO2) becoming an important and widely used clinical descriptor of gas exchange, although its full potential has not been realized. We have explored the effect of impaired gas exchange on the relationship between PIO2 and SaO2. A curve of oxygen content vs PIO2 for an ideal lung was constructed using the oxygen dissociation curve and allowing for the effect of dissolved oxygen in plasma. A plot of PIO2 vs SaO2 was derived from this content curve. The effect of impaired gas exchange (shunt and V/Q effects) on this relationship was then modelled using for shunt the equation Qs/Qt = (Cc' O2-CaO2)/(Cc' O2-CvO2) and for V/Q, a graphical method using the equation V/Q = k(Cc' O2-CvO2)/ (PIO2-PAO2) and the oxygen content curve to model the effect of a spread of V/Q ratios. A total of nine compartments were used to model the scatter of V/Q, and the size of these compartments were determined by their relative blood supply. Plots of PIO2 vs SaO2 were derived for different values of shunt and V/Q. The PIO2 vs SaO2 curve reflected the shape of the oxygen dissociation curve but lay to the right by PIO2-PAO2. Shunt caused a depression of the plateau of this curve with relatively little lateral movement, whereas a low mean V/Q ratio caused a marked rightwards lateral displacement. Increased IogSD Q caused a flattening of the relationship. The combined effect of shunt and a spread of V/Q ratios caused both lateral and vertical displacements. Thus a series of simple measurements of PIO2 and SaO2 gave information about both shunt and V/Q abnormality. PMID:8260294

  11. Catalyst containing oxygen transport membrane

    Science.gov (United States)

    Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

    2012-12-04

    A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

  12. Oxygen and carbon dioxide sensing

    Science.gov (United States)

    Ren, Fan (Inventor); Pearton, Stephen John (Inventor)

    2012-01-01

    A high electron mobility transistor (HEMT) capable of performing as a CO.sub.2 or O.sub.2 sensor is disclosed, hi one implementation, a polymer solar cell can be connected to the HEMT for use in an infrared detection system. In a second implementation, a selective recognition layer can be provided on a gate region of the HEMT. For carbon dioxide sensing, the selective recognition layer can be, in one example, PEI/starch. For oxygen sensing, the selective recognition layer can be, in one example, indium zinc oxide (IZO). In one application, the HEMTs can be used for the detection of carbon dioxide and oxygen in exhaled breath or blood.

  13. Formation of ethylene from methionine. Reactivity of radiolytically produced oxygen radicals and effect of substrate activation

    International Nuclear Information System (INIS)

    Ethylene was determined by gas chromatography after reaction of radiolytically produced OH and 02- radicals with methionine, methionine + pyridoxal phosphate and S-adenosyl-methionine (SAM). Both oxygen radicals, alone or in combination, liberate ethylene from methionine and methionine/pyridoxal phosphate. From SAM ethyline was primarily produced by the combined attack of OH and H202 or 02-. (author)

  14. Hydrocodone Combination Products

    Science.gov (United States)

    Codiclear DH® (as a combination product containing Guaifenesin, Hydrocodone) ... EndaCof XP® (as a combination product containing Guaifenesin, Hydrocodone) ... Entuss® (as a combination product containing Guaifenesin, Hydrocodone)

  15. Nanofibre materials producing singlet oxygen

    Czech Academy of Sciences Publication Activity Database

    Mosinger, J.; Jirsák, O.; Kubát, Pavel; Lang, Kamil; Mosinger, B.

    Praha : Elmarco, 2007, s. 68-71. ISBN 978-80-254-0476-8. [Nano for the 3rd. millenium. Praha (CZ), 17.10.2007-18.10.2007] R&D Projects: GA ČR GA203/07/1424; GA ČR(CZ) GA203/06/1244 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502 Keywords : nanofiber materials * singlet oxygen Subject RIV: CF - Physical ; Theoretical Chemistry

  16. Oxygen Delivering Biomaterials for Tissue Engineering

    Science.gov (United States)

    Farris, Ashley L.; Rindone, Alexandra N.; Grayson, Warren L.

    2016-01-01

    Tissue engineering (TE) has provided promising strategies for regenerating tissue defects, but few TE approaches have been translated for clinical applications. One major barrier in TE is providing adequate oxygen supply to implanted tissue scaffolds, since oxygen diffusion from surrounding vasculature in vivo is limited to the periphery of the scaffolds. Moreover, oxygen is also an important signaling molecule for controlling stem cell differentiation within TE scaffolds. Various technologies have been developed to increase oxygen delivery in vivo and enhance the effectiveness of TE strategies. Such technologies include hyperbaric oxygen therapy, perfluorocarbon- and hemoglobin-based oxygen carriers, and oxygen-generating, peroxide-based materials. Here, we provide an overview of the underlying mechanisms and how these technologies have been utilized for in vivo TE applications. Emerging technologies and future prospects for oxygen delivery in TE are also discussed to evaluate the progress of this field towards clinical translation.

  17. High-Pressure Oxygen Concentrator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA desires to generate and store gases including oxygen and nitrogen at sub-critical conditions as a part of its lunar and spacecraft atmospheric systems. Oxygen...

  18. Medical Oxygen Concentrator for Microgravity Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We have all seen people carrying portable oxygen tanks or concentrators to provide critical life support respiratory oxygen. Heavy, bulky, and for O2 concentrators,...

  19. Magnetocaloric Pumping of Liquid Oxygen

    Science.gov (United States)

    Immer, Christopher; Kandula, Max; Lane, John; Youngquist, Robert

    2004-01-01

    The field-induced force density on a magnetic fluid is proportional to the magnetic susceptibility times the gradient of the magnetic field squared. The direction of the force is towards increasing magnetic field (positive gradient). Applying a magnetic field to a magnetic fluid will result in a force from all directions towards the location of peak field. Since the magnetic field is conservative and there are no magnetic monopoles, the net field-induced force on any fluid of constant susceptibly will be zero. The only manner to obtain a nonzero net field-induced force is to vary the susceptibility of the fluid. At the gas/liquid interface of liquid oxygen, the susceptibility varies drastically, and the exploitation of the resultant large net forces. An alternative method of varying the magnetic susceptibility is to vary the temperature of the fluid. The magnetic susceptibility of paramagnetic liquid oxygen obeys the Curie-Weiss law: it is inversely proportional to temperature. By applying a temperature gradient in the presence of a symmetric magnetic field, a nonzero net force results. Much of the theory of the so-called Magnetocaloric Effect has previously been developed for and applied to ferromagnetic fluids, or ferrofluids, but is readily applied to paramagnetic liquid oxygen.

  20. [The story of oxygen (2)].

    Science.gov (United States)

    Marini, F; Radin, S; Tenchini, P

    1985-04-01

    The authors, in this second part of the oxygen story, resolutely cross the borders of the biophysical field, and face the origins and becoming of life, the stages of which are synthesized in "casket" terms, unusual for surgeons: "protobionts", "procariots", "cyanobacteria", "chlorophyll", "caroteonides", "fermentation", "anaerobic glycolysis", "eucariots", "respiratory chain", "mitocondria". This is not an unconventional biological exercise, but the effort to give clinics a more legible ground, a sort of common denominator of the most different pathologies, and, among these ones, at the first place, just those of the specialistic branch, also less frequenter of biology, that is, surgery. This common denominator, the oxygen radicals represent the emerging apex of, like the peak of an iceberg, in fact, can be only investigated through an exasperated "philogenetic" recovering. Such process of "archaeology" seems to be the only suitable to supply us the cipher-key of the ambiguous, shifty character of oxygen, and entrust us with a cultural patrimony being unique as it is spendable in an immediate clinical future. PMID:4017137

  1. Oxygen Gas Phase Abundance Revisited

    CERN Document Server

    André, M K; Howk, J C; Ferlet, R; Désert, J M; Hébrard, G; Lacour, S; Lecavelier-des-Etangs, A; Vidal-Madjar, A; Moos, H W

    2003-01-01

    We present new measurements of the interstellar gas-phase oxygen abundance along the sight lines towards 19 early-type galactic stars at an average distance of 2.6 kpc. We derive O {\\small I} column densities from {\\it HST}/STIS observations of the weak 1355 \\AA intersystem transition. We derive total hydrogen column densities [N(H {\\small I})+2N(H$_2$)] using {\\it HST}/STIS observations of \\lya and {\\it FUSE} observations of molecular hydrogen. The molecular hydrogen content of these sight lines ranges from f(H$_2$) = 2N(H$_2$)/[N(H {\\small I})+2N(H$_2$)] = 0.03 to 0.47. The average $$ of 6.3$\\times10^{21}$ cm$^{-2}$ mag$^{-1}$ with a standard deviation of 15% is consistent with previous surveys. The mean oxygen abundance along these sight lines, which probe a wide range of galactic environments in the distant ISM, is 10$^6$ \\oh = $408 \\pm 13$ (1 $\\sigma$ in the mean). %$({\\rm O/H})_{gas} = 408 \\pm 14$(1 $\\sigma$). We see no evidence for decreasing gas-phase oxygen abundance with increasing molecular hydroge...

  2. A Novel Electrochemical Oxygen Sensor for Determination of Ultra-low Oxygen Contents in Molten Metal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel electrochemical oxygen sensor has been developed by using La-Al2O3 as solid electrolyte and Cr+Cr2O3 as reference electrode. The sensor not only can be used as normal oxygen sensor but also as an ultra-low oxygen sensor. Especially, it is very sensitive to measure ultra-low oxygen in molten metal. For estimating the accuracy of La-Al2O3 oxygen sensor, two series of oxygen activities in molten iron at different oxygen contents and different temperature were measured by both La-Al2O3 oxygen sensor and ZrO2 oxygen sensor. The theoretical values of oxygen activities in molten iron (3.30%C, in mass fraction) at 1723K and 1745K were also evaluated for comparing the measuring results of two sensors. At last, the error of measurement for La-Al2O3 oxygen sensor was discussed too.

  3. The role of oxygen and water on molybdenum nanoclusters for electro catalytic ammonia production

    Directory of Open Access Journals (Sweden)

    Jakob G. Howalt

    2014-01-01

    Full Text Available The presence of water often gives rise to oxygen adsorption on catalyst surfaces through decomposition of water and the adsorbed oxygen or hydroxide species often occupy important surfaces sites, resulting in a decrease or a total hindrance of other chemical reactions taking place at that site. In this study, we present theoretical investigations of the influence of oxygen adsorption and reduction on pure and nitrogen covered molybdenum nanocluster electro catalysts for electrochemical reduction of N2 to NH3 with the purpose of understanding oxygen and water poisoning of the catalyst. Density functional theory calculations are used in combination with the computational hydrogen electrode approach to calculate the free energy profile for electrochemical protonation of O and N2 species on cuboctahedral Mo13 nanoclusters. The calculations show that the molybdenum nanocluster will preferentially bind oxygen over nitrogen and hydrogen at neutral bias, but under electrochemical reaction conditions needed for nitrogen reduction, oxygen adsorption is severely weakened and the adsorption energy is comparable to hydrogen and nitrogen adsorption. The potentials required to reduce oxygen off the surface are −0.72 V or lower for all oxygen coverages studied, and it is thus possible to (reactivate (partially oxidized nanoclusters for electrochemical ammonia production, e.g., using a dry proton conductor or an aqueous electrolyte. At lower oxygen coverages, nitrogen molecules can adsorb to the surface and electrochemical ammonia production via the associative mechanism is possible at potentials as low as −0.45 V to −0.7 V.

  4. The role of beaded activated carbon's surface oxygen groups on irreversible adsorption of organic vapors.

    Science.gov (United States)

    Jahandar Lashaki, Masoud; Atkinson, John D; Hashisho, Zaher; Phillips, John H; Anderson, James E; Nichols, Mark

    2016-11-01

    The objective of this study is to determine the contribution of surface oxygen groups to irreversible adsorption (aka heel formation) during cyclic adsorption/regeneration of organic vapors commonly found in industrial systems, including vehicle-painting operations. For this purpose, three chemically modified activated carbon samples, including two oxygen-deficient (hydrogen-treated and heat-treated) and one oxygen-rich sample (nitric acid-treated) were prepared. The samples were tested for 5 adsorption/regeneration cycles using a mixture of nine organic compounds. For the different samples, mass balance cumulative heel was 14 and 20% higher for oxygen functionalized and hydrogen-treated samples, respectively, relative to heat-treated sample. Thermal analysis results showed heel formation due to physisorption for the oxygen-deficient samples, and weakened physisorption combined with chemisorption for the oxygen-rich sample. Chemisorption was attributed to consumption of surface oxygen groups by adsorbed species, resulting in formation of high boiling point oxidation byproducts or bonding between the adsorbates and the surface groups. Pore size distributions indicated that different pore sizes contributed to heel formation - narrow micropores (<7Å) in the oxygen-deficient samples and midsize micropores (7-12Å) in the oxygen-rich sample. The results from this study help explain the heel formation mechanism and how it relates to chemically tailored adsorbent materials. PMID:27295065

  5. Oxygen-carbon nanotubes as a chemotherapy sensitizer for paclitaxel in breast cancer treatment.

    Directory of Open Access Journals (Sweden)

    Yongkun Wang

    Full Text Available To study the in vivo and in vitro effects of adding oxygen carbon nanotubes (CNTs to chemotherapy for breast cancer.MCF-7 and SK-BR-3 breast cancer cells were co-cultured with paclitaxel and then exposed to oxygen-CNTs under hypoxic conditions. Cell proliferation, viability, and apoptosis rate were analyzed. Hypoxia-inducible factor-1 alpha (HIF-1α expression was measured using reverse transcription-polymerase chain reaction (RT-PCR and western blot. Nude mice were used as a human breast cancer model to explore the impact of oxygen-CNTs on the in vivo chemotherapeutic effect of paclitaxel.Oxygen-CNTs had no significant effects on the growth of breast cancer cells under normoxia and hypoxia. However, in the hypoxic environment, oxygen-CNTs significantly enhanced the inhibitory effect of paclitaxel on cell proliferation, as well as the apoptosis rate. Under hypoxia, downregulation of HIF-1α and upregulation of caspase-3, caspase-8, caspase-9, LC3 and Beclin-1 were observed when paclitaxel was combined with oxygen-CNT. Furthermore, addition of oxygen-CNTs to chemotherapy was found to significantly reduce tumor weight in the tumor-bearing mice model.Oxygen-CNTs can significantly increase the chemotherapeutic effect of paclitaxel on breast cancer cells. Oxygen-CNTs may be a potential chemosensitizer in breast cancer therapy.

  6. Verification of oxygen cross section data for oil well logging applications

    International Nuclear Information System (INIS)

    The carbon/oxygen logging tools used in the petroleum industry to determine the ratio of the number of carbon to the number of oxygen nuclei in the formation surrounding the tool, and in this way the oil to water ratio, relies on a good knowledge on the oxygen and carbon cross sections in particular. The objective of this work is to investigate the importance of the oxygen cross section with respect to the needs of the oil well logging applications, and to state the quality of the presently available evaluations. For a few typical oil well logging geometries the radiation transport calculations combined with the cross section sensitivity analyses were performed. The sensitivity profiles of the 3 to 7 MeV gamma rays in the detectors (roughly corresponding to the energy windows used for carbon and oxygen logging) with respect to the major nuclear reaction types of oxygen very obtained, indicating the nuclear data important for oil well logging. Finally, the FNS/JAERI Liquid Oxygen Time-of-Flight benchmark experiment, involving the measurement of the angular neutron spectra leading from a 20 cm liquid oxygen slab, and covering the energy range relevant for oil well logging applications, was analyzed in order to determine the actual state-of-the-art of the oxygen nuclear data. The benchmark experiment was analyzed using the discrete ordinates transport code DORT and compared to the results of the Monte Carlo code MCNP-4B. (author)

  7. Effect of oxygen concentration in modified atmosphere packaging on color and texture of beef patties cooked to different temperatures.

    Science.gov (United States)

    Bao, Yulong; Puolanne, Eero; Ertbjerg, Per

    2016-11-01

    Patties were made from raw minced beef after storage for 6days in modified atmosphere (0, 20, 40, 60, and 80% oxygen) to study the combined effect of oxygen concentration and cooking temperature on hardness and color. Increased oxygen concentrations generally led to larger (P<0.01) thiobarbituric acid-reactive substances (TBARS) values, greater (P<0.01) loss of free thiols and more formation of cross-linked myosin heavy chain. Hardness of cooked patties was generally lower (P<0.01) without oxygen. Premature browning of cooked patties was observed already at a relative low oxygen concentration of 20%. The internal redness of cooked patties decreased (P<0.05) with increasing oxygen concentrations and increasing cooking temperatures. Mean particle size (D(3,2)) of homogenized cooked meat generally increased (P<0.05) with increasing cooking temperatures and increasing oxygen concentrations, and particle size was correlated (r=0.80) with hardness of cooked patties. PMID:27341620

  8. Optimal oxygen saturation in premature infants

    OpenAIRE

    Meayoung Chang

    2011-01-01

    There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebra...

  9. Oxygen, nitric oxide and articular cartilage

    OpenAIRE

    Fermor, B.; Christensen, S. E.; I Youn; J M Cernanec; C M Davies; Weinberg, J. B.

    2007-01-01

    Molecular oxygen is required for the production of nitric oxide (NO), a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O...

  10. Iridium-Doped Ruthenium Oxide Catalyst for Oxygen Evolution

    Science.gov (United States)

    Valdez, Thomas I.; Narayan, Sri R.; Billings, Keith J.

    2011-01-01

    NASA requires a durable and efficient catalyst for the electrolysis of water in a polymer-electrolyte-membrane (PEM) cell. Ruthenium oxide in a slightly reduced form is known to be a very efficient catalyst for the anodic oxidation of water to oxygen, but it degrades rapidly, reducing efficiency. To combat this tendency of ruthenium oxide to change oxidation states, it is combined with iridium, which has a tendency to stabilize ruthenium oxide at oxygen evolution potentials. The novel oxygen evolution catalyst was fabricated under flowing argon in order to allow the iridium to preferentially react with oxygen from the ruthenium oxide, and not oxygen from the environment. Nanoparticulate iridium black and anhydrous ruthenium oxide are weighed out and mixed to 5 18 atomic percent. They are then heat treated at 300 C under flowing argon (in order to create an inert environment) for a minimum of 14 hours. This temperature was chosen because it is approximately the creep temperature of ruthenium oxide, and is below the sintering temperature of both materials. In general, the temperature should always be below the sintering temperature of both materials. The iridium- doped ruthenium oxide catalyst is then fabricated into a PEM-based membrane- electrode assembly (MEA), and then mounted into test cells. The result is an electrolyzer system that can sustain electrolysis at twice the current density, and at the same efficiency as commercial catalysts in the range of 100-200 mA/sq cm. At 200 mA/sq cm, this new system operates at an efficiency of 85 percent, which is 2 percent greater than commercially available catalysts. Testing has shown that this material is as stable as commercially available oxygen evolution catalysts. This means that this new catalyst can be used to regenerate fuel cell systems in space, and as a hydrogen generator on Earth.

  11. Properties of reactive oxygen species by quantum Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Andrea [Dipartimento di Fisica, La Sapienza - Università di Roma, Piazzale Aldo Moro 2, 00185 Rome (Italy); Trout, Bernhardt L. [Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139 (United States); Guidoni, Leonardo, E-mail: leonardo.guidoni@univaq.it [Dipartimento di Scienze Fisiche e Chimiche, Università degli studi de L' Aquila, Via Vetoio, 67100 Coppito, L' Aquila (Italy)

    2014-07-07

    The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of chemistry, biology, and atmospheric science. Nevertheless, the electronic structure of such species is a challenge for ab initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution, and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal Power (JAGP) wave function ansatz, which has been recently shown to effectively describe the statical and dynamical correlation of different molecular systems. In particular, we have studied the oxygen molecule, the superoxide anion, the nitric oxide radical and anion, the hydroxyl and hydroperoxyl radicals and their corresponding anions, and the hydrotrioxyl radical. Overall, the methodology was able to correctly describe the geometrical and electronic properties of these systems, through compact but fully-optimised basis sets and with a computational cost which scales as N{sup 3} − N{sup 4}, where N is the number of electrons. This work is therefore opening the way to the accurate study of the energetics and of the reactivity of large and complex oxygen species by first principles.

  12. Effects of carbogen plus fractionated irradiation on KHT tumor oxygenation

    International Nuclear Information System (INIS)

    Background and purpose: Numerous studies have demonstrated improvements in the oxygenation of tumor cells following both irradiation and carbogen breathing. The current studies were initiated to measure the combined effects of carbogen inhalation plus single and multi-dose irradiation on tumor oxygen availability, to better define the underlying physiological relationships. Materials and methods: Using KHT murine sarcomas, radiation was delivered to the tumor-bearing legs of non-anesthetized mice. Tumors were quick-frozen prior to or following single or multifraction irradiation and carbogen breathing, and intravascular HbO2 saturation profiles were determined cryospectrophotometrically. Results: HbO2 levels for blood vessels located near the tumor surface initially decreased following 10 Gy irradiation, then increased and remained elevated. Interior HbO2 levels remained unchanged. Following 2.5 Gy, HbO2 changes were minimal. At 24 h following 10 Gy, HbO2 levels were significantly increased compared to non-irradiated controls, and carbogen breathing produced no additional benefit. At 24 h following five fractions of 2 Gy, HbO2 levels throughout the tumor volume were significantly higher in carbogen breathing animals than in air breathing controls. Conclusions: Although peripheral blood vessels demonstrated substantial improvements in oxygenation following irradiation, oxygen availability nearer the tumor center remained at very low levels. The utility of carbogen in enhancing tumor oxygen availability was maintained following five clinically relevant fractions. At higher doses, radiation-induced enhancements in HbO2 levels overshadowed the carbogen effect. For either air or carbogen breathing, a decrease in the percentage of vessels with very low oxygen content did not appear to be a major factor in the reoxygenation of the KHT tumor

  13. Oxygen diffusion in glasses and ceramic materials

    International Nuclear Information System (INIS)

    A survey is given on the published works to study oxygen diffusion in glasses and ceramic materials in the last years. In the first part methods are described for the measurement of oxygen diffusion coefficients and in the second part the published reports on oxygen diffusion in glasses, ceramic and other oxides are discussed. The most important results are summarized in different tables. (author)

  14. 29 CFR 1910.104 - Oxygen.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Oxygen. 1910.104 Section 1910.104 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Hazardous Materials § 1910.104 Oxygen. (a) Scope. This section applies to the installation of bulk oxygen systems on industrial and institutional consumer premises....

  15. 41 CFR 50-204.67 - Oxygen.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Oxygen. 50-204.67 Section..., Vapors, Fumes, Dusts, and Mists § 50-204.67 Oxygen. The in-plant transfer, handling, storage, and utilization of oxygen as a liquid or a compressed gas shall be in accordance with Compressed Gas...

  16. 46 CFR 147.85 - Oxygen.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Oxygen. 147.85 Section 147.85 Shipping COAST GUARD... Special Requirements for Particular Materials § 147.85 Oxygen. (a) Eighty five cubic meters (3000 standard cubic feet) or less of oxygen may be on board any vessel. (b) More than 85 m3 (3000 standard cubic...

  17. Aerobic growth at nanomolar oxygen concentrations

    DEFF Research Database (Denmark)

    Stolper, Daniel Aaron; Revsbech, Niels Peter; Canfield, Donald Eugene

    2010-01-01

    Molecular oxygen (O2) is the second most abundant gas in the Earth’s atmosphere, but in many natural environments, its concentration is reduced to low or even undetectable levels. Although low-oxygen-adapted organisms define the ecology of low-oxygen environments, their capabilities are not fully...

  18. 30 CFR 57.5015 - Oxygen deficiency.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Oxygen deficiency. 57.5015 Section 57.5015..., Physical Agents, and Diesel Particulate Matter Air Quality-Underground Only § 57.5015 Oxygen deficiency. Air in all active workings shall contain at least 19.5 volume percent oxygen....

  19. 46 CFR 154.1360 - Oxygen analyzer.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Oxygen analyzer. 154.1360 Section 154.1360 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Instrumentation § 154.1360 Oxygen analyzer. The vessel must have a portable analyzer that measures oxygen...

  20. 46 CFR 197.452 - Oxygen cleaning.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Oxygen cleaning. 197.452 Section 197.452 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS....452 Oxygen cleaning. The diving supervisor shall ensure that equipment used with oxygen or...

  1. Hyperbaric oxygen preconditioning protects rats against CNS oxygen toxicity.

    Science.gov (United States)

    Arieli, Yehuda; Kotler, Doron; Eynan, Mirit; Hochman, Ayala

    2014-06-15

    We examined the hypothesis that repeated exposure to non-convulsive hyperbaric oxygen (HBO) as preconditioning provides protection against central nervous system oxygen toxicity (CNS-OT). Four groups of rats were used in the study. Rats in the control and the negative control (Ctl-) groups were kept in normobaric air. Two groups of rats were preconditioned to non-convulsive HBO at 202 kPa for 1h once every other day for a total of three sessions. Twenty-four hours after preconditioning, one of the preconditioned groups and the control rats were exposed to convulsive HBO at 608 kPa, and latency to CNS-OT was measured. Ctl- rats and the second preconditioned group (PrC-) were not subjected to convulsive HBO exposure. Tissues harvested from the hippocampus and frontal cortex were evaluated for enzymatic activity and nitrotyrosine levels. In the group exposed to convulsive oxygen at 608 kPa, latency to CNS-OT increased from 12.8 to 22.4 min following preconditioning. A significant decrease in the activity of glutathione reductase and glucose-6-phosphate dehydrogenase, and a significant increase in glutathione peroxidase activity, was observed in the hippocampus of preconditioned rats. Nitrotyrosine levels were significantly lower in the preconditioned animals, the highest level being observed in the control rats. In the cortex of the preconditioned rats, a significant increase was observed in glutathione S-transferase and glutathione peroxidase activity. Repeated exposure to non-convulsive HBO provides protection against CNS-OT. The protective mechanism involves alterations in the enzymatic activity of the antioxidant system and lower levels of peroxynitrite, mainly in the hippocampus. PMID:24675062

  2. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, R.; Hauss, H.; Buchholz, F.; Melzner, F.

    2015-10-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  3. Influences of oxygen partial pressure on YBCO grain growth by a zone melting method

    International Nuclear Information System (INIS)

    This study reports investigation on influences of Y endash Ba endash Cu endash O compounds solidification under different oxygen partial pressures by a zone melting method. In Y endash Ba endash Cu endash O system, P(O2) ranged from 0.02 to 1 atm, following reaction occurred during heating: YBa2Cu3O6+δ(Y123)→Y2BaCuO5(Y211)+L. With an increase of oxygen partial pressure or decrease of pulling rate, the morphology of solidified interface changed from mushy to equiaxed, cellular, and planar. The continuous Y123 grains were readily obtained under high oxygen partial pressure. Based on the constitutional supercooling theory and combining the result of the yttrium solubility limit for different oxygen partial pressures, the influences of oxygen partial pressure on Y123 morphological evolution were clarified. copyright 1996 Materials Research Society

  4. Identifying combustion intermediates in premixed MTBE/gasoline/oxygen flame probed via synchrotron radiation

    Institute of Scientific and Technical Information of China (English)

    YAO Chunde; QI Fei; LI Jing; LI Qi; JI Qing; HUANG Chaoqun; WEI Lixia; WANG Jing; TIAN Zhenyu; LI Yuyang

    2007-01-01

    Molecular-beam sampling mass spectrometry (MBMS) combined with tunable synchrotron radiation photoionization technique offers obvious advantages for the study of flame chemistry over other techniques because of the precision measurement of the combustion intermediates and products in flame.In this paper,the results to identify combustion intermediates in low-pressure premixed gasoline/oxygen flame with the synchrotron radiation were reported.Based on the results obtained,the formation process of five products and the difference between gasoline/oxygen and MTBE/gasoline/oxygen flame were emphatically analyzed.The results achieved provide data basis for the analysis of intermediates and radicals in flame,and are helpful to establish the kinetic modeling of gasoline/oxygen and MTBE/gasoline/oxygen flames.

  5. Atomic structures and oxygen dynamics of CeO2 grain boundaries

    Science.gov (United States)

    Feng, Bin; Sugiyama, Issei; Hojo, Hajime; Ohta, Hiromichi; Shibata, Naoya; Ikuhara, Yuichi

    2016-02-01

    Material performance is significantly governed by grain boundaries (GBs), a typical crystal defects inside, which often exhibit unique properties due to the structural and chemical inhomogeneity. Here, it is reported direct atomic scale evidence that oxygen vacancies formed in the GBs can modify the local surface oxygen dynamics in CeO2, a key material for fuel cells. The atomic structures and oxygen vacancy concentrations in individual GBs are obtained by electron microscopy and theoretical calculations at atomic scale. Meanwhile, local GB oxygen reduction reactivity is measured by electrochemical strain microscopy. By combining these techniques, it is demonstrated that the GB electrochemical activities are affected by the oxygen vacancy concentrations, which is, on the other hand, determined by the local structural distortions at the GB core region. These results provide critical understanding of GB properties down to atomic scale, and new perspectives on the development strategies of high performance electrochemical devices for solid oxide fuel cells.

  6. Biochemical Oxygen Demand and Dissolved Oxygen. Training Module 5.105.2.77.

    Science.gov (United States)

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with the azide modification of the Winkler dissolved oxygen test and the electronic dissolved oxygen meter test procedures for determining the dissolved oxygen and the biochemical oxygen demand of a wastewater sample. Included are…

  7. Separation of hydrogen and oxygen isotopes by membrane method

    International Nuclear Information System (INIS)

    Water enriched with deuterium or heavy oxygen plays an important role in research and technology. Heavy water (HDO, D2O) is used in nuclear technology and research and its role will become even more important should nuclear fusion ever be used for energy production. Over the past few years the world has witnessed a continuously increasing demand for enriched oxygen isotopes, especially 18O, due to a large consumption of H218O by positron emission tomography (PET), a new medical diagnostic technique used principally for tumour detection. PET uses short-lived positron emitters, like carbon-11, nitrogen-13, oxygen-15 and fluorine-18 incorporated into biochemically active tracer molecules absorbed preferentially by the tumour. Several different target materials are used for a production of these isotopes, among them water enriched in 18O. The methods of hydrogen and oxygen isotopes enrichment are expensive and energy-consuming; the separation processes are characterised by low separation factors, which very often introduce hazardous substances, poisonous or explosive (H2S, NH3, H2). There is a need to explore new methods, less energy-consuming and more safe. In this work, the unit H/D and 16O/18O separation factors in permeation of natural water with phase transition (membrane distillation) were determined and the influence of process parameters on their values was defined. Isotope effects of permeation were compared with vapour pressure isotope effects (VPIE). The experimental separation factors of H/D and 16O/18O in permeation through hydrophobic PTFE membrane were higher than those for water distillation. Since distillation is the only method for heavy oxygen production the process has particular importance for separation. The description of phenomena occurring in permeation of water isotopomers through porous PTFE membranes was presented. The isotope effect of permeation was performed as a combination of two effects: VPIE and the effect related to the transport of

  8. Adiabatic Compression of Oxygen: Real Fluid Temperatures

    Science.gov (United States)

    Barragan, Michelle; Wilson, D. Bruce; Stoltzfus, Joel M.

    2000-01-01

    The adiabatic compression of oxygen has been identified as an ignition source for systems operating in enriched oxygen atmospheres. Current practice is to evaluate the temperature rise on compression by treating oxygen as an ideal gas with constant heat capacity. This paper establishes the appropriate thermodynamic analysis for the common occurrence of adiabatic compression of oxygen and in the process defines a satisfactory equation of state (EOS) for oxygen. It uses that EOS to model adiabatic compression as isentropic compression and calculates final temperatures for this system using current approaches for comparison.

  9. Estimation of Biological Oxygen Demand and Chemical Oxygen Demand for Combined Sewer Systems Using Synchronous Fluorescence Spectra

    OpenAIRE

    Dae-Hee Park; Tae-Hwan Lee; Bo-Mi Lee; Jin Hur

    2010-01-01

    Real-time monitoring of water quality for sewer system is required for efficient sewer network design because it provides information on the precise loading of pollutant to wastewater treatment facilities and the impact of loading on receiving water. In this study, synchronous fluorescence spectra and its first derivatives were investigated using a number of wastewater samples collected in sewer systems in urban and non-urban areas, and the optimum fluorescence feature was explored for the es...

  10. Direct Oxygen Abundances for Low Luminosity LVL Galaxies

    CERN Document Server

    Berg, Danielle A; Marble, Andrew R; van Zee, Liese; Engelbracht, Charles W; Lee, Janice C; Kennicutt, Robert C; Jr.,; Calzetti, Daniela; Dale, Daniel A; Johnson, Benjamin D

    2012-01-01

    We present MMT spectroscopic observations of HII regions in 42 low luminosity galaxies in the LVL. For 31 galaxies, we measured the temperature sensitive [O III] line at a strength of 4 sigma or greater, and thus determine direct oxygen abundances. Our results provide the first direct estimates of oxygen abundance for 19 galaxies. Oxygen abundances were compared to B-band and 4.5 micron luminosities and stellar masses in order to characterize the luminosity-metallicity (L-Z) and mass-metallicity (M-Z) relationships at low-luminosity. We present and analyze a "Combined Select" sample composed of 38 objects (drawn from our parent sample and the literature) with direct oxygen abundances and reliable distance determinations (TRGB or Ceph). Consistent with previous studies, the B-band and 4.5 micron L-Z relationships were found to be 12+log(O/H)=(6.27+/-0.21)+(-0.11+/-0.01)M_B and 12+log(O/H)=(6.10+/-0.21)+(-0.10+/-0.01)M_[4.5] (sigma=0.15 and 0.14). For this sample, we derive a M-Z relationship of 12+log(O/H)=(5....

  11. Pulmonary ventilation: dynamic MRI with inhalation of molecular oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Hatabu, Hiroto E-mail: hatabu@oasis.rad.upenn.edu; Tadamura, Eiji; Chen Qun; Stock, Klaus W.; Li, Wei; Prasad, Pottumarthi V.; Edelman, Robert R

    2001-03-01

    We have recently demonstrated a non-invasive technique to visualize pulmonary ventilation in humans with inhalation of molecular oxygen as a paramagnetic contrast agent. In the current study, T1 shortening of lung tissue by inhalation of oxygen was observed (P<0.001). The T1 values of lung tissue were also correlated with arterial blood oxygen pressure (PaO{sub 2}) in a pig, resulting in excellent correlation (r{sup 2}=0.997). Dynamic wash-in and wash-out MR ventilation images as well as dynamic wash-in wash-out signal intensity versus time curves were obtained. The mean wash-in decay constants were 26.8{+-}10.5 s in the right lung, and 26.3{+-}9.5 s in the left lung. The mean wash-out decay constants were 23.3{+-}11.3 s in the right lung, and 20.8{+-}10.5 s in the left lung. Dynamic assessment of pulmonary ventilation is feasible using oxygen-enhanced MR imaging, which could provide dynamic MR ventilation-perfusion imaging in combination with recently developed MR perfusion imaging technique, and thus a robust tool for the study of pulmonary physiology and pathophysiology.

  12. Electrochemical oxygen reduction catalysed by Ni3(hexaiminotriphenylene)2

    Science.gov (United States)

    Miner, Elise M.; Fukushima, Tomohiro; Sheberla, Dennis; Sun, Lei; Surendranath, Yogesh; Dincă, Mircea

    2016-03-01

    Control over the architectural and electronic properties of heterogeneous catalysts poses a major obstacle in the targeted design of active and stable non-platinum group metal electrocatalysts for the oxygen reduction reaction. Here we introduce Ni3(HITP)2 (HITP=2, 3, 6, 7, 10, 11-hexaiminotriphenylene) as an intrinsically conductive metal-organic framework which functions as a well-defined, tunable oxygen reduction electrocatalyst in alkaline solution. Ni3(HITP)2 exhibits oxygen reduction activity competitive with the most active non-platinum group metal electrocatalysts and stability during extended polarization. The square planar Ni-N4 sites are structurally reminiscent of the highly active and widely studied non-platinum group metal electrocatalysts containing M-N4 units. Ni3(HITP)2 and analogues thereof combine the high crystallinity of metal-organic frameworks, the physical durability and electrical conductivity of graphitic materials, and the diverse yet well-controlled synthetic accessibility of molecular species. Such properties may enable the targeted synthesis and systematic optimization of oxygen reduction electrocatalysts as components of fuel cells and electrolysers for renewable energy applications.

  13. Electrochemical oxygen reduction catalysed by Ni3(hexaiminotriphenylene)2

    Science.gov (United States)

    Miner, Elise M.; Fukushima, Tomohiro; Sheberla, Dennis; Sun, Lei; Surendranath, Yogesh; Dincă, Mircea

    2016-01-01

    Control over the architectural and electronic properties of heterogeneous catalysts poses a major obstacle in the targeted design of active and stable non-platinum group metal electrocatalysts for the oxygen reduction reaction. Here we introduce Ni3(HITP)2 (HITP=2, 3, 6, 7, 10, 11-hexaiminotriphenylene) as an intrinsically conductive metal-organic framework which functions as a well-defined, tunable oxygen reduction electrocatalyst in alkaline solution. Ni3(HITP)2 exhibits oxygen reduction activity competitive with the most active non-platinum group metal electrocatalysts and stability during extended polarization. The square planar Ni-N4 sites are structurally reminiscent of the highly active and widely studied non-platinum group metal electrocatalysts containing M-N4 units. Ni3(HITP)2 and analogues thereof combine the high crystallinity of metal-organic frameworks, the physical durability and electrical conductivity of graphitic materials, and the diverse yet well-controlled synthetic accessibility of molecular species. Such properties may enable the targeted synthesis and systematic optimization of oxygen reduction electrocatalysts as components of fuel cells and electrolysers for renewable energy applications. PMID:26952523

  14. Effect of chest physiotherapy on oxygen saturation in patients with cystic fibrosis.

    OpenAIRE

    Pryor, J A; Webber, B. A.; Hodson, M E

    1990-01-01

    Decreasing arterial oxygen saturation has been reported in patients with cystic fibrosis during postural drainage when this was combined with other manoeuvres, which did not, however, include thoracic expansion exercises or pauses for relaxation and breathing control. When these features were included in an active cycle of breathing techniques during postural drainage in 20 patients with cystic fibrosis there was no fall in arterial oxygen saturation during the procedure (mean values 87.1%, 8...

  15. Effect of oxygen minimum zone formation on communities of marine protists

    OpenAIRE

    Orsi, William; Song, Young C.; Hallam, Steven; Edgcomb, Virginia

    2012-01-01

    Changes in ocean temperature and circulation patterns compounded by human activities are leading to oxygen minimum zone (OMZ) expansion with concomitant alteration in nutrient and climate active trace gas cycling. Here, we report the response of microbial eukaryote populations to seasonal changes in water column oxygen-deficiency using Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island British Columbia, as a model ecosystem. We combine small subunit ribosomal RNA gene s...

  16. Contrast Enhancement for in vivo Visible Reflectance Imaging of Tissue Oxygenation

    OpenAIRE

    Crane, Nicole J.; Schultz, Zachary D.; Levin, Ira W.

    2007-01-01

    Results are presented illustrating a straightforward algorithm to be used for real time monitoring of oxygenation levels in blood cells and tissue based on the visible spectrum of hemoglobin. Absorbance images obtained from the visible reflection of white light through separate red and blue bandpass filters recorded by monochrome CCDs are combined to create enhanced images that suggest a quantitative correlation to the degree of oxygenated and deoxygenated hemoglobin in red blood cells. The f...

  17. Heterogeneous ceramic interfaces in solid oxide fuel cells and dense oxygen permeable membranes

    OpenAIRE

    Faaland, Sonia

    2000-01-01

    Solid oxide fuel cells and oxygen permeable membranes have received considerable attention during the last decade due to the increasing demand for electrical energy and easily transportable fuels combined with the requirement of low emission of CO2. This work concentrates on the stability of ceramic interfaces in general, and more specifically to heterophase solid state interfaces related to solid oxide fuel cells and oxygen permeable membranes. Reaction mechanisms are discussed and requireme...

  18. Effect of Oxygen Content on the Sintering Behaviour of Silver Nanopowders Produced by Inert Gas Condensation

    OpenAIRE

    TÜRKER, Mehmet

    2002-01-01

    Polymer-based materials are made electrically conductive by combining with a particulate conductive material. Instead of using high aspect-ratio conventional fillers, such as fibres and flakes, highly porous silver nanopowders were produced for using in polymer matrix composites. Such powders were produced by inert gas condensation (IGC) in a helium atmosphere with or without additional oxygen. The effect of oxygen content on the size, morphology and specific surface area of the particle...

  19. Tissue oxygenation and muscular substrate turnover in two subjects with high hemoglobin oxygen affinity.

    OpenAIRE

    Wranne, B; Berlin, G; Jorfeldt, L; Lund, N.

    1983-01-01

    Oxygen transport to and substrate turnover in leg muscle were studied at rest and during light and heavy upright bicycle exercise in two brothers with a hereditary hemoglobinopathy associated with high oxygen affinity (P50 = 13 mmHg). Femoral venous oxygen tension was below normal and femoral venous oxygen saturation above normal at rest and during exercise. Thus, the arterial-femoral venous oxygen saturation difference was decreased. Despite a compensatory increase in hemoglobin concentratio...

  20. Oxygen Generation from Carbon Dioxide for Advanced Life Support

    Science.gov (United States)

    Bishop, s. R.; Duncan, K. L.; Hagelin-Weaver, H. E.; Neal, L.; Paul, H. L.; Wachsman, E. D.

    2007-01-01

    The partial electrochemical reduction of CO2 using ceramic oxygen generators (COGs) is well known and has been studied. Conventional COGs use yttria-stabilized zirconia (YSZ) electrolytes and operate at temperatures greater than 700 C (1, 2). Operating at a lower temperature has the advantage of reducing the mass of the ancillary components such as insulation. Moreover, complete reduction of metabolically produced CO2 (into carbon and oxygen) has the potential of reducing oxygen storage weight if the oxygen can be recovered. Recently, the University of Florida developed ceramic oxygen generators employing a bilayer electrolyte of gadolinia-doped ceria and erbia-stabilized bismuth oxide (ESB) for NASA s future exploration of Mars (3). The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. These results indicate that this technology could be adapted to CO2 removal from a spacesuit and other applications in which CO2 removal is an issue. This strategy for CO2 removal in advanced life support systems employs a catalytic layer combined with a COG so that the CO2 is reduced completely to solid carbon and oxygen. First, to reduce the COG operating temperature, a thin, bilayer electrolyte was employed. Second, to promote full CO2 reduction while avoiding the problem of carbon deposition on the COG cathode, a catalytic carbon deposition layer was designed and the cathode utilized materials shown to be coke resistant. Third, a composite anode was used consisting of bismuth ruthenate (BRO) and ESB that has been shown to have high performance (4). The inset of figure 1 shows the conceptual design of the tubular COG and the rest of the figure shows schematically the test apparatus. Figure 2 shows the microstructure of a COG tube prior to testing. During testing, current is applied across the cell and initially CuO is reduced to copper metal by electrochemical pumping. Then the oxygen source becomes the CO/CO2. This presentation

  1. Oxygen reduction on carbon supported platinum catalysts in high temperature polymer electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Hjuler, Hans Aage; Bjerrum, Niels

    2000-01-01

    Oxygen reduction on carbon supported platinum catalysts has been investigated in H3PO4, H3PO4-doped Nafion and polybenzimidazole (PBI) polymer electrolytes in a temperature range up to 190 degrees C. Compared with pure H3PO4, the combination of H3PO4 and polymer electrolytes can significantly...... improve the oxygen reduction kinetics due to increased oxygen solubility and suppressed adsorption of phosphoric acid anions. Further enhancement of the catalytic activity can be obtained by operating the polymer electrolytes at higher temperatures. Efforts have been made to develop a polymer electrolyte...

  2. A Cabin Air Separator for EVA Oxygen

    Science.gov (United States)

    Graf, John C.

    2011-01-01

    Presently, the Extra-Vehicular Activities (EVAs) conducted from the Quest Joint Airlock on the International Space Station use high pressure, high purity oxygen that is delivered to the Space Station by the Space Shuttle. When the Space Shuttle retires, a new method of delivering high pressure, high purity oxygen to the High Pressure Gas Tanks (HPGTs) is needed. One method is to use a cabin air separator to sweep oxygen from the cabin air, generate a low pressure/high purity oxygen stream, and compress the oxygen with a multistage mechanical compressor. A main advantage to this type of system is that the existing low pressure oxygen supply infrastructure can be used as the source of cabin oxygen. ISS has two water electrolysis systems that deliver low pressure oxygen to the cabin, as well as chlorate candles and compressed gas tanks on cargo vehicles. Each of these systems can feed low pressure oxygen into the cabin, and any low pressure oxygen source can be used as an on-board source of oxygen. Three different oxygen separator systems were evaluated, and a two stage Pressure Swing Adsorption system was selected for reasons of technical maturity. Two different compressor designs were subjected to long term testing, and the compressor with better life performance and more favorable oxygen safety characteristics was selected. These technologies have been used as the basis of a design for a flight system located in Equipment Lock, and taken to Preliminary Design Review level of maturity. This paper describes the Cabin Air Separator for EVA Oxygen (CASEO) concept, describes the separator and compressor technology trades, highlights key technology risks, and describes the flight hardware concept as presented at Preliminary Design Review (PDR)

  3. Synthesis and characterization of gallium-based perovskitetype dense membrane with oxygen semipermeability

    Institute of Scientific and Technical Information of China (English)

    丛铀; 邵宗平; 杨维慎; 熊国兴; 林励吾

    2001-01-01

    La0.15Sr0.85Ga0.3Fe0.7O3-δ(LSGFO) and La0.15Sr0.85Co0.3Fe0.7O3-δ(LSCFO) mixed oxygen-ion and electron conducting oxides were synthesized by using a combined EDTA and citrate complexing method, and the corresponding dense membranes were fabricated. The properties of the oxide powders and membranes were characterized with combined SEM, XRD, H2-TPR, O2-TPD techniques, mechanical strength and oxygen permeation measurement. The results showed that LSGFO had much higher thermochemical stability than LSCFO due to the higher valence stability of Ga3+. After the temperature-programmed reduction by 5% H2 in Ar from 20℃to 1020℃, the basic perovskite structure of LSGFO was successfully preserved. LSGFO also favors the oxygen vacancy formation better than LSCFO. Oxygen permeation measurement demonstrated that LSGFO had higher oxygen permeation flux than LSCFO, but they had similar activation energy for oxygen transportation, with a value of 110 and 117 kJ ?mol-1, respectively. The difference in oxygen permeation f

  4. Research on Technology of Pressure Pretreatment with Oxygen for Refractory Gold Ores

    Institute of Scientific and Technical Information of China (English)

    Liu Shengming; Sun Tichang; Chen Jinghe; Wang Dianzuo

    2007-01-01

    An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.

  5. Hyperbaric oxygen and wound healing

    Directory of Open Access Journals (Sweden)

    Sourabh Bhutani

    2012-01-01

    Full Text Available Hyperbaric oxygen therapy (HBOT is the use of 100% oxygen at pressures greater than atmospheric pressure. Today several approved applications and indications exist for HBOT. HBOT has been successfully used as adjunctive therapy for wound healing. Non-healing wounds such as diabetic and vascular insufficiency ulcers have been one major area of study for hyperbaric physicians where use of HBOT as an adjunct has been approved for use by way of various studies and trials. HBOT is also indicated for infected wounds like clostridial myonecrosis, necrotising soft tissue infections, Fournier′s gangrene, as also for traumatic wounds, crush injury, compartment syndrome, compromised skin grafts and flaps and thermal burns. Another major area of application of HBOT is radiation-induced wounds, specifically osteoradionecrosis of mandible, radiation cystitis and radiation proctitis. With the increase in availability of chambers across the country, and with increasing number of studies proving the benefits of adjunctive use for various kinds of wounds and other indications, HBOT should be considered in these situations as an essential part of the overall management strategy for the treating surgeon.

  6. Mitigation strategies of intergranular corrosion in systems of reactors of water boiling (BWR). Combined action of the chemistry of the hydrogen and the oxygen; Estrategias de mitigacion de la corrosion intergranular en sistemas de reactores de agua en ebullicion (BWR). Accion combinada de la quimica del hidrogeno y del oxigeno

    Energy Technology Data Exchange (ETDEWEB)

    Verdugo, M.

    2015-07-01

    Inter-Granular Stress Corrosion cracking (IGSCC) in austenitic stainless steel and in austenitic nickel-based alloys has been the subject of many studies the aim of which was to resolve one of the main problems faced by BWR nuclear power plants since the 1960s. This corrosion phenomenon is the result of the combined action of three factors: sensitization of the material, high local stresses and an aggressive medium. This paper deals with these factors separately and analyzes the oxidative chemistry of BWR reactors (aggressivity of the medium) as one the main causes if IGSCC. (Author)

  7. SUPPORTED DENSE CERAMIC MEMBRANES FOR OXYGEN SEPARATION

    Energy Technology Data Exchange (ETDEWEB)

    Timothy L. Ward

    2003-03-01

    This project addresses the need for reliable fabrication methods of supported thin/thick dense ceramic membranes for oxygen separation. Some ceramic materials that possess mixed conductivity (electronic and ionic) at high temperature have the potential to permeate oxygen with perfect selectivity, making them very attractive for oxygen separation and membrane reactor applications. In order to maximize permeation rates at the lowest possible temperatures, it is desirable to minimize diffusional limitations within the ceramic by reducing the thickness of the ceramic membrane, preferably to thicknesses of 10 {micro}m or thinner. It has proven to be very challenging to reliably fabricate dense, defect-free ceramic membrane layers of such thickness. In this project we are investigating the use of ultrafine SrCo{sub 0.5}FeO{sub x} (SCFO) powders produced by aerosol pyrolysis to fabricate such supported membranes. SrCo{sub 0.5}FeO{sub x} is a ceramic composition that has been shown to have desirable oxygen permeability, as well as good chemical stability in the reducing environments that are encountered in some important applications. Our approach is to use a doctor blade procedure to deposit pastes prepared from the aerosol-derived SCFO powders onto porous SCFO supports. We have previously shown that membrane layers deposited from the aerosol powders can be sintered to high density without densification of the underlying support. However, these membrane layers contained large-scale cracks and open areas, making them unacceptable for membrane purposes. In the past year, we have refined the paste formulations based on guidance from the ceramic tape casting literature. We have identified a multicomponent organic formulation utilizing castor oil as dispersant in a solvent of mineral spirits and isopropanol. Other additives were polyvinylbutyral as binder and dibutylphthalate as plasticizer. The nonaqueous formulation has superior wetting properties with the powder, and

  8. Taurus Littrow Pyroclastic Deposit-An Optimum Feedstock for Lunar Oxygen

    Science.gov (United States)

    Allen, Carlton C.

    2014-01-01

    Future human habitation of the Moon will likely require the use of locally derived materials because of the high cost of transportation from Earth. Oxygen, extracted from oxides and silicates, is a potentially abundant lunar resource vital for life support and spacecraft propulsion. The anticipated costs of supplying all oxygen needs for a lunar base from Earth are high enough to warrant serious study of oxygen production from local resources. Over 20 different processes have been proposed for oxygen production on the Moon. Among the simplest and best studied of these processes is the reduction of oxides in lunar minerals and glass using hydrogen gas. Oxygen can be extracted from lunar soils and pyroclastic glass beads by exposing the samples to flowing hydrogen at subsolidus temperatures (approx. 1050 C). Total oxygen yield is directly correlated to the sample's abundance of FeO, but is not correlated to the abundance of any other oxide. Oxygen is extracted predominantly from FeO, with lesser contributions from TiO2 and SiO2. Oxygen yield is independent of soil maturity. All major FeO-bearing phases contribute oxygen, with extraction from ilmenite and glass significantly more efficient than from olivine and pyroxene. This study demonstrates that the optimum location for a lunar resources demonstration mission can be identified, and that the oxygen yield can be predicted, using a combination of high-resolution imaging and thermal-infrared data. A mission to Taurus Littrow will encounter a deposit at least 10 m in depth with few landing hazards, a uniform composition, and a predicted oxygen yield of approximately 3 wt. %, among the highest values on the Moon.

  9. Effects of sevoflurane and propofol anesthesia in small tidal volume combined with low positive end-expiratory pressure on intrapulmonary shunt, oxygenation and inflammatory cytokines during one-lung ventilation%七氟醚和丙泊酚在小潮气量联合低呼气末正压对单肺通气时肺内分流、氧合和炎性因子的影响比较

    Institute of Scientific and Technical Information of China (English)

    吴志云; 查本俊; 王永盛; 谢平; 庄海滨

    2015-01-01

    目的 比较单肺通气过程中,七氟醚和丙泊酚对实施小潮气量联合低呼气末正压通气(positive end-expiratorypressure,PEEP)患者肺内分流、氧合和炎性因子的影响.方法 择期行右侧开胸手术的食管癌患者76例,美国麻醉医师协会(ASA)分级Ⅰ~Ⅲ级,采用随机数字表法将患者分为丙泊酚组(P组)和七氟醚组(S组),每组38例.P组持续输注丙泊酚,S组持续吸入七氟醚,维持脑电双频指数(bispectal index,BIS)40~50,其他用药两组相同.分别在手术开始前(T0)和单肺通气后30(T1)、60(T2)、90 min(T3)以及膨肺后双肺通气30(T4)、60 min(T5),采集颈内静脉和桡动脉血样进行血气分析,计算肺内分流率(Qs/Qt)、相邻两个时间点动脉血氧分压(arterial partial pressure of oxygen,PaO2)和Qs/Qt的变化值(△PaO2和△Qs/Qt),并测定白细胞介素(interleukin,IL)-8、IL-10和肿瘤坏死因子(tumor necrosis factor,TNF)-α的浓度.结果 与T0比较:两组T1~T5时Qs/Qt、IL-8、IL-10、TNF-α均升高,PaO2降低(P<0.05).与T1比较:两组T4、T5时PaO2明显升高,Qs/Qt明显降低(P<0.05);P组IL-8、IL-10、TNF-α在T3~T5时升高,而S组在T2~T5时升高(P<0.05).两组间比较:△PaO2[P组(-1.3±7.7)、(-1.9±6.0),S组(-4.3±4.3)、(-3.1±5.3)]和△Qs/Qt[P组(0.06-±0.57)、(0.07±0.34),S组(0.71±0.86)、(0.72±0.95)]在T1~T2、T2~T3时间段比较差异均有统计学意义(P<0.05),S组IL-8、IL-10、TNF-α在T2~T5时均高于P组(P<0.05).结论 单肺通气期间实施小潮气量联合低PEEP时,丙泊酚比七氟醚对肺内分流和氧合影响更小,产生炎性因子少.%Objective To compare the effects of sevoflurane and propofol anesthesia on intrapulmonary shunt,oxygenation and inflammatory cytokines in small tidal volume combined with low positive end-expiratory pressure (PEEP) during one-lung ventilation.Methods Seventy-six ASA Ⅰ-Ⅲ patients undergoing elective esophagus cancer resection via right

  10. Measuring tissue oxygen saturation using NIR spectroscopy

    Science.gov (United States)

    Sircan-Kucuksayan, Aslinur; Uyuklu, Mehmet; Canpolat, Murat

    2014-05-01

    Tissue oxygen saturation (StO2) is known quite useful parameter for medical applications. A spectroscopic method has been developed to diagnose pathologic tissues due to lack of normal blood circulation by measuring tissue oxygen saturation. In the study, human blood samples with different level of oxygen saturations have been prepared and spectra were taken using an optical fiber probe to investigate correlation between the oxygen saturations and the spectra. The experimental set up for the spectroscopic measurements was consists of a miniature NIR light spectrometer, an optical fiber probe, a halogen-tungsten light source and a laptop. A linear correlation between the oxygen saturation of the blood samples and the ratio of the light of wavelengths 660 nm to 790 nm has been found from the spectra. Then, oxygen saturations of the blood samples were estimated from the spectroscopic measurements within an error of 2.9%. Furthermore, it has been shown that the linear dependence between the ratio and the oxygen saturation of the blood samples was valid for the blood samples with different hematocrits. Tissue oxygen saturation has been estimated from the spectroscopic measurements were taken from the fingers of healthy volunteers using the correlation between the spectra and blood oxygen saturation. The tissue StO2 measured was 80% as expected. The technique developed to measure tissue oxygen saturation has potential to diagnose premalignant tissues, follow up prognosis of cancerous tissues, and evaluation of ischemia reperfusion tissues.

  11. The influence of ultraviolet blood irradiation and oxygenation on oxygen free radicals metabolism in rabbits with soman intoxication

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To investigate the effect of ultraviolet blood irradiation and oxygenation (UBIO) on the metabolism of oxygen free radicals in rabbits with acute soman intoxication. Methods: One hundred rabbits were randomly divided into 5 groups: normal control group, intoxication group, routine therapy group, UBIO therapy group and combined therapy group. After 14 d, the concentration of malondiadehyde (MDA) and activity of superoxide dismutase (SOD), glutathionperoxidase (GSH-Px), catalase (CAT)and total antioxidative capacity (T-AOC) in serum were determined respectively. Results: Compared with the normal control group, the concentration of MDA and activity of CAT in the intoxication group were significantly higher (P < 0. 05 ), but SOD, GSH-Px activity and T-AOC were significantly lower (P<0.05). After UBIO or combined therapy, serum MDA level was significantly lower in comparison with intoxication group (P<0.05), but the activity of SOD, GSH-Px, CAT and T AOC were higher than intoxication group(P<0.05). Conclusion: There is an obvious oxygen free radical injury in rabbits with acute soman intoxication. UBIO can improve the antioxidation ability of rabbits and may be applied to treat acute soman intoxication as adjunctive therapy.

  12. Meso- to submesocale oxygen variability and lateral oxygen fluxes in the oxygen minimum zone of the eastern tropical North Atlantic

    Science.gov (United States)

    Hahn, Johannes; Brandt, Peter; Krahmann, Gerd

    2015-04-01

    The oxygen minimum zone (OMZ) of the eastern tropical North Atlantic (ETNA) is located between the oxygen-rich equatorial region and the Cape Verde Frontal Zone at 20°N in a depth range between 300m - 700m. Its southern boundary is predominantly set by the equatorial zonal current system, where the northernmost current branch is represented by the eastward flowing North Equatorial Counter Current / North Equatorial Undercurrent (NECC/NEUC) at 5°N. Recent studies have shown enhanced oxygen variability for this location at the OMZ core depth which is generated due to mesoscale stirring induced by tropical instability waves as well as seasonal variability of the NECC/NEUC. An extensive measurement program was carried out in the past decade consisting of repeat ship sections as well as moored and glider observations along the 23°W section in order to study oxygen ventilation and oxygen variability in the ETNA OMZ regime. Moored and shipboard observations of oxygen and velocity reveal an eddy-driven northward oxygen flux towards the OMZ core, which results in an oxygen supply of up to 60% of the observed oxygen consumption. Based on the several year long moored observations at 5°N and 8°N, a seasonal variability of the eddy-driven meridional oxygen flux is found. Corresponding frequency spectra of the mooring time series are used to discuss time scales of enhanced variability of oxygen and meridional velocity. In this study, we explicitly present a measurement program which was conducted at 5°N, 23°W consisting of a triangular mooring array (Nov. 2012 - Apr. 2014) as well as a glider swarm experiment with a fleet of 3 gliders (Nov. - Dec. 2012). Based on this data set, a variogram of oxygen is derived to study spatial scales on the meso- to submesoscale in the NECC/NEUC regime.

  13. Nitrogen and Oxygen Isotopic Studies of the Marine Nitrogen Cycle

    Science.gov (United States)

    Casciotti, Karen L.

    2016-01-01

    The marine nitrogen cycle is a complex web of microbially mediated reactions that control the inventory, distribution, and speciation of nitrogen in the marine environment. Because nitrogen is a major nutrient that is required by all life, its availability can control biological productivity and ecosystem structure in both surface and deep-ocean communities. Stable isotopes of nitrogen and oxygen in nitrate and nitrite have provided new insights into the rates and distributions of marine nitrogen cycle processes, especially when analyzed in combination with numerical simulations of ocean circulation and biogeochemistry. This review highlights the insights gained from dual-isotope studies applied at regional to global scales and their incorporation into oceanic biogeochemical models. These studies represent significant new advances in the use of isotopic measurements to understand the modern nitrogen cycle, with implications for the study of past ocean productivity, oxygenation, and nutrient status.

  14. Oxygenation properties and isoform diversity of snake hemoglobins

    DEFF Research Database (Denmark)

    Storz, Jay F.; Natarajan, Chandrasekhar; Moriyama, Hideaki;

    2015-01-01

    Available data suggest that snake hemoglobins (Hbs) are characterized by a combination of unusual structural and functional properties relative to the Hbs of other amniote vertebrates, including oxygenation-linked tetramer- dimer dissociation. However, standardized comparative data are lacking for...... snake Hbs, and the Hb isoform composition of snake red blood cells has not been systematically characterized. Here we present the results of an integrated analysis of snake Hbs and the underlying - and -type globin genes to characterize 1) Hb isoform composition of definitive erythrocytes, and 2) the...... oxygenation properties of isolated isoforms as well as composite hemolysates. We used species from three families as subjects for experimental studies of Hb function: South American rattlesnake, Crotalus durissus (Viperidae); Indian python, Python molurus (Pythonidae); and yellow-bellied sea snake, Pelamis...

  15. Birth control pills - combination

    Science.gov (United States)

    Birth control pills help keep you from getting pregnant. When taken daily, they are one of the most effective ... periods Treat acne Prevent ovarian cancer Combination birth control pills contain both estrogen and progestin. Some combination ...

  16. Familial combined hyperlipidemia

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/000396.htm Familial combined hyperlipidemia To use the sharing features on this page, please enable JavaScript. Familial combined hyperlipidemia is a disorder that is passed down ...

  17. 40 CFR 80.83 - Renewable oxygenate requirements.

    Science.gov (United States)

    2010-07-01

    ... oxygenate blender who uses the oxygenate is able to establish in the form of documentation that the... under § 80.41; except that (ii) The renewable oxygenate added by a downstream oxygenate blender shall... (3). (f) Recordkeeping. Any refiner or importer, or any oxygenate blender who blends oxygenate...

  18. COMBINE 2 seminar

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Jacobsen, Kim

    1995-01-01

    A seminar about the COMBINE project was described. Further, the project was described in generel, i.e. the COMBINE´s data model (IDM), the data exchange system (DES) and the different I/O-systems included in COMBINE 2......A seminar about the COMBINE project was described. Further, the project was described in generel, i.e. the COMBINE´s data model (IDM), the data exchange system (DES) and the different I/O-systems included in COMBINE 2...

  19. Methodology for the assessment of oxygen as an energy carrier

    Science.gov (United States)

    Yang, Ming Wei

    Due to the energy intensity of the oxygen generating process, the electric power grid would benefit if the oxygen generating process was consumed electric power only during low demand periods. Thus, the question to be addressed in this study is whether oxygen production and/or usage can be modified to achieve energy storage and/or transmission objectives at lower cost. The specific benefit to grid would be a leveling, over time, of the demand profile and thus would require less installation capacity. In order to track the availability of electricity, a compressed air storage unit is installed between the cryogenic distillation section and the main air compressor of air separation unit. A profit maximizing scheme for sizing storage inventory and related equipments is developed. The optimum scheme is capable of market responsiveness. Profits of steel maker, oxy-combustion, and IGCC plants with storage facilities can be higher than those plants without storage facilities, especially, at high-price market. Price tracking feature of air storage integration will certainly increase profit margins of the plants. The integration may push oxy-combustion and integrated gasification combined cycle process into economic viability. Since oxygen is used in consumer sites, it may generate at remote locations and transport to the place needed. Energy losses and costs analysis of oxygen transportation is conducted for various applications. Energy consumptions of large capacity and long distance GOX and LOX pipelines are lower than small capacity pipelines. However, transportation losses and costs of GOX and LOX pipelines are still higher than electricity transmission.

  20. Cathodic oxygen reduction catalyzed by bacteria in microbial fuel cells.

    Science.gov (United States)

    Rabaey, Korneel; Read, Suzanne T; Clauwaert, Peter; Freguia, Stefano; Bond, Philip L; Blackall, Linda L; Keller, Jurg

    2008-05-01

    Microbial fuel cells (MFCs) have the potential to combine wastewater treatment efficiency with energetic efficiency. One of the major impediments to MFC implementation is the operation of the cathode compartment, as it employs environmentally unfriendly catalysts such as platinum. As recently shown, bacteria can facilitate sustainable and cost-effective cathode catalysis for nitrate and also oxygen. Here we describe a carbon cathode open to the air, on which attached bacteria catalyzed oxygen reduction. The bacteria present were able to reduce oxygen as the ultimate electron acceptor using electrons provided by the solid-phase cathode. Current densities of up to 2.2 A m(-2) cathode projected surface were obtained (0.303+/-0.017 W m(-2), 15 W m(-3) total reactor volume). The cathodic microbial community was dominated by Sphingobacterium, Acinetobacter and Acidovorax sp., according to 16S rRNA gene clone library analysis. Isolates of Sphingobacterium sp. and Acinetobacter sp. were obtained using H(2)/O(2) mixtures. Some of the pure culture isolates obtained from the cathode showed an increase in the power output of up to three-fold compared to a non-inoculated control, that is, from 0.015+/-0.001 to 0.049+/-0.025 W m(-2) cathode projected surface. The strong decrease in activation losses indicates that bacteria function as true catalysts for oxygen reduction. Owing to the high overpotential for non-catalyzed reduction, oxygen is only to a limited extent competitive toward the electron donor, that is, the cathode. Further research to refine the operational parameters and increase the current density by modifying the electrode surface and elucidating the bacterial metabolism is warranted. PMID:18288216

  1. Oxygen supply maps for hypoxic microenvironment visualization in prostate cancer

    Science.gov (United States)

    Rupp, Niels J.; Schüffler, Peter J.; Zhong, Qing; Falkner, Florian; Rechsteiner, Markus; Rüschoff, Jan H.; Fankhauser, Christian; Drach, Matthias; Largo, Remo; Tremp, Mathias; Poyet, Cedric; Sulser, Tullio; Kristiansen, Glen; Moch, Holger; Buhmann, Joachim; Müntener, Michael; Wild, Peter J.

    2016-01-01

    Background: Intratumoral hypoxia plays an important role with regard to tumor biology and susceptibility to radio- and chemotherapy. For further investigation of hypoxia-related changes, areas of certain hypoxia must be reliably detected within cancer tissues. Pimonidazole, a 2-nitroimindazole, accumulates in hypoxic tissue and can be easily visualized using immunohistochemistry. Materials and Methods: To improve detection of highly hypoxic versus normoxic areas in prostate cancer, immunoreactivity of pimonidazole and a combination of known hypoxia-related proteins was used to create computational oxygen supply maps of prostate cancer. Pimonidazole was intravenously administered before radical prostatectomy in n = 15 patients, using the da Vinci robot-assisted surgical system. Prostatectomy specimens were immediately transferred into buffered formaldehyde, fixed overnight, and completely embedded in paraffin. Pimonidazole accumulation and hypoxia-related protein expression were visualized by immunohistochemistry. Oxygen supply maps were created using the normalized information from pimonidazole and hypoxia-related proteins. Results: Based on pimonidazole staining and other hypoxia.related proteins (osteopontin, hypoxia-inducible factor 1-alpha, and glucose transporter member 1) oxygen supply maps in prostate cancer were created. Overall, oxygen supply maps consisting of information from all hypoxia-related proteins showed high correlation and mutual information to the golden standard of pimonidazole. Here, we describe an improved computer-based ex vivo model for an accurate detection of oxygen supply in human prostate cancer tissue. Conclusions: This platform can be used for precise colocalization of novel candidate hypoxia-related proteins in a representative number of prostate cancer cases, and improve issues of single marker correlations. Furthermore, this study provides a source for further in situ tests and biochemical investigations PMID:26955501

  2. Quantification of oxygen and carbon in high Tc superconducting films by (α,α) elastic resonance technique

    International Nuclear Information System (INIS)

    The quantification of oxygen and carbon in high-temperature (Tc) superconducting oxide thin films was made by employing elastic resonance in He backscattering analysis. A method combining the oxygen resonance technique and channeling was presented for measuring the nature of the oxygen disorder near the surface and the interface in a YBCO superconducting film grown on an MgO substrate. The oxygen resonance technique was used to quantify the oxygen profiling in the metal/YBCO contacts, showing that Zr and Nb act as sinks to oxygen from YBCO films and are oxidized in the forms Zr/ZrO2/YBCO/MgO and Nb0.2O/YBCO/MgO after annealing in a vacuum at 350oC. We combined the carbon and oxygen resonances to determine the carbon contamination and oxygen concentration changes on the YBCO surface after coating and baking the photoresist. Residual carbon on the surface and a thin layer of oxygen depletion near the YBCO surface have been observed. The residual carbon in Bi2Sr2CaCu2O8 films made by the decomposition of metallo-organic precursors was quantified using carbon resonance. (author)

  3. Modifiable Combining Functions

    OpenAIRE

    Cohen, Paul; Shafer, Glenn; Shenoy, Prakash P.

    2013-01-01

    Modifiable combining functions are a synthesis of two common approaches to combining evidence. They offer many of the advantages of these approaches and avoid some disadvantages. Because they facilitate the acquisition, representation, explanation, and modification of knowledge about combinations of evidence, they are proposed as a tool for knowledge engineers who build systems that reason under uncertainty, not as a normative theory of evidence.

  4. Oxygen diffusion in bilayer polymer films

    DEFF Research Database (Denmark)

    Poulsen, Lars; Zebger, Ingo; Tofte, Jannik Pentti;

    2004-01-01

    Experiments to quantify oxygen diffusion have been performed on polymer samples in which a film of poly(ethylene-co-norbornene) was cast onto a film of polystyrene which, in turn, was cast onto an oxygen-impermeable substrate. In the technique employed, the time evolution of oxygen transport...... through the film of poly(ethylene-co-norbornene) and into the polystyrene film was monitored using the phosphorescence of singlet oxygen as a spectroscopic probe. To analyze the data, it was necessary to solve Fick's second law of diffusion for both polymer films. Tractable analytical and numerical...... solutions were obtained for the problem. Moreover, the numerical solution is sufficiently general that it can be used to simulate oxygen concentration profiles in films consisting of more than two layers. Data obtained from the bilayer films yield a diffusion coefficient for oxygen in poly...

  5. [How did the earth's oxygen atmosphere originate?].

    Science.gov (United States)

    Schäfer, G

    2004-09-01

    The planet earth did not carry an oxygen atmosphere from the beginning. Though oxygen could arise from radiation mediated water splitting, these processes were not efficient enough to create a global gas atmosphere. Oxygen in the latter is a product of the photosynthetic activity of early green organisms. Only after biological mass-formation of oxygen the UV-protective ozone layer could develop, then enabeling life to move from water onto land. This took billions of years. The basics of the processes of biological oxygen liberation and utilization are described in the following as well as the importance of their steady state equilibrium. Also a hint is given to oxygen as a toxic compound though being a chemical prerequisite for aerobic life on earth. PMID:15490337

  6. Robust high temperature oxygen sensor electrodes

    DEFF Research Database (Denmark)

    Lund, Anders

    Platinum is the most widely used material in high temperature oxygen sensor electrodes. However, platinum is expensive and the platinum electrode may, under certain conditions, suffer from poisoning, which is detrimental for an oxygen sensor. The objective of this thesis is to evaluate electrode...... materials as candidates for robust oxygen sensor electrodes. The present work focuses on characterising the electrochemical properties of a few electrode materials to understand which oxygen electrode processes are limiting for the response time of the sensor electrode. Three types of porous platinum......-Dansensor. The electrochemical properties of the electrodes were characterised by electrochemical impedance spectroscopy (EIS), and the structures were characterised by x-ray diffraction and electron microscopy. At an oxygen partial pressures of 0.2 bar, the response time of the sensor electrode was determined by oxygen...

  7. Can erythropoietin improve tumor oxygenation?

    Energy Technology Data Exchange (ETDEWEB)

    Kelleher, D.K.; Thews, O.; Vaupel, P. [Mainz Univ. (Germany). Inst. of Physiology and Pathophysiology

    1998-12-01

    Tumor growth, oxygenation and radiosensitivity were investigated in a series of studies in which anemia was induced in rats either by the development of a hemorrhagic ascites or by a single dose of carboplatin, which resulted in reductions in the hemoglobin concentration of 30%. The development of both the tumor- and chemotherapy-induced forms of anemia could be prevented by the s.c. administration of recombinant human erythropoietin (rhEPO; 1000 IU/kg, 3 times per week over 14 days). Seven days before pO{sub 2} measurements, DS-sarcomas were implanted s.c. on the hind foot dorsum. With both anemia models, tumor growth did not differ between anemic animals and animals treated with rhEPO. Tumor oxygenation was measured polarographically using O{sub 2}-sensitive needle electrodes and pO{sub 2} histography. In anemic animals, tumor oxygenation was poorer compared to untreated controls. The reduction could be partially reversed by rhEPO treatment, but not fully compensated. These findings suggested that rhEPO treatment can improve tumor oxygenation by increasing the O{sub 2} availability to tumor tissue. Further experiments therefore assessed the possibility of enhancing the efficacy of a single radiation dose (10 Gy) by rhEPO treatment of anemic animals. While anemic animals showed decreased radiosensitivity, prevention of anemia by rhEPO treatment resulted in a significant increase in tumor radiosensitivity, although again a full recovery to radiosensitivity levels found in non-anemic animals was not achieved. (orig.) [Deutsch] Um den Einfluss einer Anaemie auf das Wachstum, die Gewebeoxygenierung und die Strahlensensibilitaet von Tumoren der Ratte zu untersuchen, wurde entweder durch Erzeugung eines haemorrhagischen Tumoraszites oder durch einmalige Gabe von Carboplatin (45 mg/kg i.v.) die Haemoglobinkonzentration des Blutes um 30% erniedrigt (normochrome normozytaere Anaemie). In einer zweiten Versuchsgruppe konnte sowohl beim Vorliegen eines haemorrhagischen

  8. Control of Dissolved Oxygen in Stirred Bioreactors

    OpenAIRE

    Åkesson, Mats; Hagander, Per

    1998-01-01

    This report discusses control of dissolved oxygen in a bioreactor where the oxygen supply is manipulated using the stirrer speed. In batch and fed-batch cultivations the operating conditions change significantly which may cause tuning problems. Analysis using a linearized process model shows that the process dynamics is mainly affected by changes in the volumetric oxygen transfer coefficient $K_La$. % To account for the process variations, a control strategy based on PID control and gain sche...

  9. The enigmatic reaction of flavins with oxygen

    OpenAIRE

    Chaiyen, Pimchai; Fraaije, Marco W.; Mattevi, Andrea

    2012-01-01

    The reaction of flavoenzymes with oxygen remains a fascinating area of research because of its relevance for reactive oxygen species (ROS) generation. Several exciting recent studies provide consistent mechanistic clues about the specific functional and structural properties of the oxidase and monooxygenase flavoenzymatic systems. Specifically, the spatial arrangement of the reacting oxygen that is in direct contact with the flavin group is emerging as a crucial factor that differentiates bet...

  10. Zaria Universal Oxygenator Holder Phase I

    OpenAIRE

    Sunday Adoga Edaigbini; Ibrahim Zira Delia; Muhammad Balarabe Aminu

    2014-01-01

    Introduction: The conduct of cardiopulmonary bypass surgery requires the use of equipment and devices like the oxygenator. The oxygenator comes in different makes and each manufacturer customizes the carrier or ′holder′ of this device specific to their design. Aim: This paper presents an innovation designed to overcome the need to purchase a different holder for every oxygenator thereby cutting the cost. Materials and Methods: A sheet of iron measuring 1.9 cm (width) × 0.1 cm (thickness) was ...

  11. Turbulent oxygen flames in type Ia supernovae

    OpenAIRE

    Aspden, Andrew; Bell, J.; Woosley, S.

    2011-01-01

    In previous studies, we examined turbulence-flame interactions in carbon-burning thermonuclear flames in Type Ia supernovae. In this study, we consider turbulence-flame interactions in the trailing oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen flame. Scaling arguments analogous to the carbon flames are presented and then compared agains...

  12. Oxygen neutronization in accreting white dwarfs

    OpenAIRE

    Bravo Guil, Eduardo; Isern Vilaboy, Jordi; Labay, Javier; Canal Masgoret, Ramon

    1983-01-01

    Solid carbon-oxygen white dwarf cores have been shown to be likely initial configurations for collapse to neutron star densities. Solidification seems to entail carbon/oxygen separation, with oxygen settling at the star's center and carbon being confined to more external, lower-density layers. Electron captures on 16O are then the triggering mechanism for collapse. The authors elucidate the outcome of the complete reaction network started by those captures and derive simple expressions for ac...

  13. Novel Oxygen Scavenger Systems for Functional Coatings

    OpenAIRE

    Demicheva, Mariia

    2015-01-01

    This thesis work was aimed at developing a novel oxygen scavenging material suitable for being used in functional coatings. It provided an overview of existing oxygen scavenging systems and technologies, and defined the restriction in using them for food applications. The major objective of this study was creating, optimizing and testing oxygen scavenging substances based on polybutadiene. The study was conducted in October 2014 – January 2015 at Evonik Industries AG situated in Hanau, German...

  14. Arterialisation of transcutaneous oxygen and carbon dioxide.

    OpenAIRE

    Broadhurst, E; Helms, P; Vyas, H; Cheriyan, G

    1988-01-01

    We compared previously calculated global correction factors for oxygen and carbon dioxide arterial/transcutaneous ratios with individual in vivo calibrations from the first arterial sample. In infants beyond the neonatal period and older children in vivo calibration confers little benefit over the use of a global calibration correction factor for transcutaneous carbon dioxide, and may reduce the precision with which arterial oxygen can be estimated from transcutaneous oxygen.

  15. No oxygen delivery limitation in hepatic encephalopathy

    DEFF Research Database (Denmark)

    Gjedde, Albert; Keiding, Susanne; Vilstrup, Hendrik;

    2010-01-01

    Hepatic encephalopathy is a condition of reduced brain functioning in which both blood flow and brain energy metabolism declined. It is not known whether blood flow or metabolism is the primary limiting factor of brain function in this condition. We used calculations of mitochondrial oxygen tensi...... oxygen tensions that patients with HE were unable to utilize. We ascribe the inability to use the delivered oxygen of patients with HE to a specific inhibition associated with oxidative metabolism in mitochondria....

  16. Maintaining Optimal Oxygen Saturation in Premature Infants

    OpenAIRE

    Lau, Yoke Yen; Tay, Yih Yann; Shah, Varsha Atul; Chang, Pisun; Loh, Khuan Tai

    2011-01-01

    Introduction: Advances in technology have resulted in increasing survival rates for premature infants. Oxygen therapy is commonly used in neonatal units as part of respiratory support. The number of premature infants in our institution surviving with severe (stage ≥3) retinopathy of prematurity (ROP) prompted a review of oxygen therapy as a contributing factor. Prolonged exposure to high concentrations of oxygen may cause irreversible damage to the eyes of very-low-birth-weight preterm infant...

  17. Early oxygen-utilization and brain activity in preterm infants.

    Directory of Open Access Journals (Sweden)

    Maria Luisa Tataranno

    Full Text Available The combined monitoring of oxygen supply and delivery using Near-InfraRed spectroscopy (NIRS and cerebral activity using amplitude-integrated EEG (aEEG could yield new insights into brain metabolism and detect potentially vulnerable conditions soon after birth. The relationship between NIRS and quantitative aEEG/EEG parameters has not yet been investigated. Our aim was to study the association between oxygen utilization during the first 6 h after birth and simultaneously continuously monitored brain activity measured by aEEG/EEG. Forty-four hemodynamically stable babies with a GA < 28 weeks, with good quality NIRS and aEEG/EEG data available and who did not receive morphine were included in the study. aEEG and NIRS monitoring started at NICU admission. The relation between regional cerebral oxygen saturation (rScO2 and cerebral fractional tissue oxygen extraction (cFTOE, and quantitative measurements of brain activity such as number of spontaneous activity transients (SAT per minute (SAT rate, the interval in seconds (i.e. time between SATs (ISI and the minimum amplitude of the EEG in μV (min aEEG were evaluated. rScO2 was negatively associated with SAT rate (β=-3.45 [CI=-5.76- -1.15], p=0.004 and positively associated with ISI (β=1.45 [CI=0.44-2.45], p=0.006. cFTOE was positively associated with SAT rate (β=0.034 [CI=0.009-0.059], p=0.008 and negatively associated with ISI (β=-0.015 [CI=-0.026- -0.004], p=0.007. Oxygen delivery and utilization, as indicated by rScO2 and cFTOE, are directly related to functional brain activity, expressed by SAT rate and ISI during the first hours after birth, showing an increase in oxygen extraction in preterm infants with increased early electro-cerebral activity. NIRS monitored oxygenation may be a useful biomarker of brain vulnerability in high-risk infants.

  18. Determination of oxygen in liquid sodium

    International Nuclear Information System (INIS)

    The behaviour is analysed of a device for 'in-line' sampling and vacuum distillation. With this procedure 95 results were obtained for the solubility of oxygen in liquid sodium at temperatures between 1250 and 3000C. The correlation between the concentration of oxygen in a saturation state and the corresponding temperature is represented by: 1g C = 6,17 - 2398/T, where C expressed ppm of oxygen by weight and T is the saturation temperature in 0K. Reference is also made to the first results obtained with the electrochemical oxygen meter and the system for taking and recording data. (author)

  19. Alarm points for fixed oxygen monitors

    International Nuclear Information System (INIS)

    Oxygen concentration monitors were installed in a vault where numerous pipes carried inert cryogens and gases to the Mirror Fusion Test Facility (MFTF-B) experimental vessel at Lawrence Livermore National Laboratory (LLNL). The problems associated with oxygen-monitoring systems and the reasons why such monitors were installed were reviewed. As a result of this review, the MFTF-B monitors were set to sound an evacuation alarm when the oxygen concentration fell below 18%. We chose the 18% alarm criterion to minimize false alarms and to allow time for personnel to escape in an oxygen-deficient environment

  20. Benefits of oxygen incorporation in atomic laminates

    Science.gov (United States)

    Dahlqvist, Martin

    2016-04-01

    Atomic laminates such as MAX phases benefit from the addition of oxygen in many ways, from the formation of a protective oxide surface layer with self-healing capabilities when cracks form to the tuning of anisotropic conductivity. In this paper oxygen incorporation and vacancy formation in M 2AlC (M  =  Ti, V, Cr) MAX phases have been studied using first-principles calculations where the focus is on phase stability and electronic structure for different oxygen and/or vacancy configurations. Oxygen prefers different lattice sites depending on M-element and this can be correlated to the number of available non-bonding M d-electrons. In Ti2AlC, oxygen substitutes carbon while in Cr2AlC it is located interstitially within the Al-layer. I predict that oxygen incorporation in Ti2AlC stabilizes the material, which explains the experimentally observed 12.5 at% oxygen (x  =  0.5) in Ti2Al(C1‑x O x ). In addition, it is also possible to use oxygen to stabilize the hypothetical Zr2AlC and Hf2AlC. Hence, oxygen incorporation may be beneficial in many ways. Not only can it make a material more stable, but it also can act as a reservoir for internal self-healing with shorter diffusion paths.

  1. Oxygen Saturation Targeting and Bronchopulmonary Dysplasia.

    Science.gov (United States)

    Darlow, Brian A; Morley, Colin J

    2015-12-01

    Oxygen saturation targeting is widely used in neonatal intensive care, but the optimal target range in very preterm infants has been uncertain and is the subject of recent debate and research. This review briefly discusses the technology of oxygen monitoring and the role of oxygen toxicity in preterm infants. The background to the recent trials of oxygen saturation targeting in acute and continuing care of very preterm infants is reviewed, and the findings and implications of the recent trials, particularly with respect to bronchopulmonary dysplasia, are discussed. PMID:26593080

  2. Comparison of airline passenger oxygen systems.

    Science.gov (United States)

    Byrne, N J

    1995-08-01

    The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma. PMID:7487813

  3. Benefits of oxygen incorporation in atomic laminates

    International Nuclear Information System (INIS)

    Atomic laminates such as MAX phases benefit from the addition of oxygen in many ways, from the formation of a protective oxide surface layer with self-healing capabilities when cracks form to the tuning of anisotropic conductivity. In this paper oxygen incorporation and vacancy formation in M 2AlC (M  =  Ti, V, Cr) MAX phases have been studied using first-principles calculations where the focus is on phase stability and electronic structure for different oxygen and/or vacancy configurations. Oxygen prefers different lattice sites depending on M-element and this can be correlated to the number of available non-bonding M d-electrons. In Ti2AlC, oxygen substitutes carbon while in Cr2AlC it is located interstitially within the Al-layer. I predict that oxygen incorporation in Ti2AlC stabilizes the material, which explains the experimentally observed 12.5 at% oxygen (x  =  0.5) in Ti2Al(C1−xOx). In addition, it is also possible to use oxygen to stabilize the hypothetical Zr2AlC and Hf2AlC. Hence, oxygen incorporation may be beneficial in many ways. Not only can it make a material more stable, but it also can act as a reservoir for internal self-healing with shorter diffusion paths. (paper)

  4. Optimal oxygen saturation in premature infants

    Directory of Open Access Journals (Sweden)

    Meayoung Chang

    2011-09-01

    Full Text Available There is a delicate balance between too little and too much supplemental oxygen exposure in premature infants. Since underuse and overuse of supplemental oxygen can harm premature infants, oxygen saturation levels must be monitored and kept at less than 95% to prevent reactive oxygen species-related diseases, such as retinopathy of prematurity and bronchopulmonary dysplasia. At the same time, desaturation below 80 to 85% must be avoided to prevent adverse consequences, such as cerebral palsy. It is still unclear what range of oxygen saturation is appropriate for premature infants; however, until the results of further studies are available, a reasonable target for pulse oxygen saturation (SpO2 is 90 to 93% with an intermittent review of the correlation between SpO2 and the partial pressure of arterial oxygen tension (PaO2. Because optimal oxygenation depends on individuals at the bedside making ongoing adjustments, each unit must define an optimal target range and set alarm limits according to their own equipment or conditions. All staff must be aware of these values and adjust the concentration of supplemental oxygen frequently.

  5. Oxygen, nitric oxide and articular cartilage

    Directory of Open Access Journals (Sweden)

    B Fermor

    2007-04-01

    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  6. Workshop on Oxygen in the Terrestrial Planets

    Science.gov (United States)

    2004-01-01

    This volume contains abstracts that have been accepted for presentation at the Workshop on Oxygen in the Terrestrial Planets, July 20-23,2004, Santa Fe, New Mexico. The contents include: 1) Experimental Constraints on Oxygen and Other Light Element Partitioning During Planetary Core Formation; 2) In Situ Determination of Fe(3+)/SigmaFe of Spinels by Electron Microprobe: An Evaluation of the Flank Method; 3) The Effect of Oxygen Fugacity on Large-Strain Deformation and Recrystallization of Olivine; 4) Plagioclase-Liquid Trace Element Oxygen Barometry and Oxygen Behaviour in Closed and Open System Magmatic Processes; 5) Core Formation in the Earth: Constraints from Ni and Co; 6) Oxygen Isotopic Compositions of the Terrestrial Planets; 7) The Effect of Oxygen Fugacity on Electrical Conduction of Olivine and Implications for Earth s Mantle; 8) Redox Chemical Diffusion in Silicate Melts: The Impact of the Semiconductor Condition; 9) Ultra-High Temperature Effects in Earth s Magma Ocean: Pt and W Partitioning; 10) Terrestrial Oxygen and Hydrogen Isotope Variations: Primordial Values, Systematics, Subsolidus Effects, Planetary Comparisons, and the Role of Water; 11) Redox State of the Moon s Interior; 12) How did the Terrestrial Planets Acquire Their Water?; 13) Molecular Oxygen Mixing Ratio and Its Seasonal Variability in the Martian Atmosphere; 14) Exchange Between the Atmosphere and the Regolith of Mars: Discussion of Oxygen and Sulfur Isotope Evidence; 15) Oxygen and Hydrogen Isotope Systematics of Atmospheric Water Vapor and Meteoric Waters: Evidence from North Texas; 16) Implications of Isotopic and Redox Heterogeneities in Silicate Reservoirs on Mars; 17) Oxygen Isotopic Variation of the Terrestrial Planets; 18) Redox Exchanges in Hydrous Magma; 19) Hydrothermal Systems on Terrestrial Planets: Lessons from Earth; 20) Oxygen in Martian Meteorites: A Review of Results from Mineral Equilibria Oxybarometers; 21) Non-Linear Fractionation of Oxygen Isotopes Implanted in

  7. Alterations in oxygen transport following WR-2721

    International Nuclear Information System (INIS)

    During the Phase I clinical trials of WR-2721 and alkylating agent chemotherapy, venous blood samples were obtained prior to and immediately following the WR-2721 infusion. The authors have observed a marked increase in the oxygen saturation of venous blood following WR-2721. The highest values generally occurred within the first 2 hours after the completion of the WR-2721 infusion. No significant differences were found between the pre and post WR-2721 values for either the venous pH, CO2, or bicarbonate levels. Despite increased P/sub v/O2, the patient's heart rates, blood pressures, or respiratory rates did not change pre and post WR-2721. In 12 patients oxygen-hemoglobin dissociation curves and intracellular red cell pH's were obtained before and after WR-2721. Despite the significant increase in oxygenation of venous blood after WR-2721, there were no changes in either oxygen-hemoglobin dissociation or intracellular red cell pH to account for this increase. The oxygen consumption of peripheral blood granulocytes was measured prior to and following 15 courses of WR-2721. A marked decrease in granulocyte oxygen consumption was observed in 6/8 patients who had a significant increase in P/sub v/O2. Our preliminary investigations suggest that the increased venous blood oxygen content may be secondary to a reduction in normal tissue oxygen consumption. WR-2721 may afford protection by both decreasing oxygen consumption and delivery to normal tissues and increasing intracellular sulfhydryls

  8. Measurement of very low oxygen tensions in liquids: does the extrapolation number for mammalian survival curves decrease after x-irradiation under anoxic conditions

    International Nuclear Information System (INIS)

    Measurements of very low partial pressures of oxygen show that a vacuum degassing system combined with an oxygen consuming agent (sodium dithionite) and/or radiochemical oxygen consumption removes all of the oxygen from cells plated on glass dishes. When these cells are x-irradiated, the extrapolation number n remains the same under both aerobic and anoxic conditions, and an oxygen enhancement ratio of 3.0 is observed. Several other physical and chemical factors tested also have no effect on n. (author)

  9. The reduction and oxidation of ceria: A natural abundance triple oxygen isotope perspective

    Science.gov (United States)

    Hayles, Justin; Bao, Huiming

    2015-06-01

    Ceria (CeO2) is a heavily studied material in catalytic chemistry for use as an oxygen storage medium, oxygen partial pressure regulator, fuel additive, and for the production of syngas, among other applications. Ceria powders are readily reduced and lose structural oxygen when subjected to low pO2 and/or high temperature conditions. Such dis-stoichiometric ceria can then re-oxidize under higher pO2 and/or lower temperature by incorporating new oxygen into the previously formed oxygen site vacancies. Despite extensive studies on ceria, the mechanisms for oxygen adsorption-desorption, dissociation-association, and diffusion of oxygen species on ceria surface and within the crystal structure are not well known. We predict that a large kinetic oxygen isotope effect should accompany the release and incorporation of ceria oxygen. As the first attempt to determine the existence and the degree of the isotope effect, this study focuses on a set of simple room-temperature re-oxidation experiments that are also relevant to a laboratory procedure using ceria to measure the triple oxygen isotope composition of CO2. Triple-oxygen-isotope labeled ceria powders are heated at 700 °C and cooled under vacuum prior to exposure to air. By combining results from independent experimental sets with different initial oxygen isotope labels and using a combined mass-balance and triangulation approach, we have determined the isotope fractionation factors for both high temperature reduction in vacuum (⩽10-4 mbar) and room temperature re-oxidation in air. Results indicate that there is a 1.5‰ ± 0.8‰ increase in the δ18O value of ceria after being heated in vacuum at 700 °C for 1 h. When the vacuum is broken at room temperature, the previously heated ceria incorporates 3-19% of its final structural oxygen from air, with a δ18O value of 2.1-4.1+7.7 ‰ for the incorporated oxygen. The substantial incorporation of oxygen from air supports that oxygen mobility is high in vacancy

  10. Precision Cleaning of Oxygen Systems and Components

    Science.gov (United States)

    McLaughlin, Russell

    2009-01-01

    Currently, NASA uses Dichloropentafluoropropane (HCFC-225), a Class II ozone depleting substance (ODs), to clean contaminated oxygen systems. Starting in 20 15, the Montreal Protocols and Clean Air Act prohibit the production and importation of all hydrochlorofluorocarbons (HCFC), except for limited use in refrigeration applications. Thus, a new non-ozone depleting solvent needs to be developed for use in cleaning. Optimally, such a solvent should also be environmentally benign or green to avoid needing to replace the new solvent with yet another solvent in the future due to other environmental concerns. Work for the first year consisted of two parts. The first part was developing a method of testing the cleaning efficiency of potential solvents. Stainless steel coupons were contaminated with a known weight of various contaminants and contaminant combinations and then immersed in solvent for ten minutes. The coupons were then removed and dried in an oven until all solvent had evaporated. Once dry, the coupons were weighed and the mass of the non-volatile residue (NVR) left on the coupon was determined. The cleaning efficiency of the solvents is reported as percent cleaning, with 100% cleaning being zero NVR left on the test coupon. The second half of the first goal was to use the develop method to perform baseline testing on current solvents. The second part of the work was to begin exploring alternative cleaning solvents. A variety of hydrofluorocarbons (HFCs) were tested. Preliminary testing was also performed with ionic liquids and aqueous surfactant solutions. Once potential solvents were identified, an analysis of the performance and environmental characteristics of each was to be conducted. Four contaminants were specified for use in testing. These are Mil-Spec-H-5606 (5606), a hydraulic fluid, Mil-H-83282B (83282), another hydraulic fluid, diethylhexyl sebacate (Sebacate), and WD-40. The structures of these contaminants are all similar, with long aliphatic

  11. Dissolved oxygen imaging in a porous medium to investigate biodegradation in a plume with limited electron acceptor supply.

    Science.gov (United States)

    Huang, Wei E; Oswald, Sascha E; Lerner, David N; Smith, Colin C; Zheng, Chunmiao

    2003-05-01

    A novel combination of noninvasive imaging with an oxygen sensitive fluorescent indicator was developed to investigate the biodegradation processes occurring at the fringe of a solute plume, where the supply of oxygen was limited. A thin transparent porous matrix (156 x 120 x 3 mm) was made from quartz plates and quartz sand (212-300 microm) and enriched with acetate-degrading bacteria. A degrading plume developed from a continuous acetate source in the uniform flow field containing dissolved oxygen. Ruthenium (II)-dichlorotris(1,10-phenanthroline) (Ru(phen)3Cl2), a water-soluble fluorescent dye, was used as an indicator of dissolved oxygen. The fluorescence intensity was dependent on the concentration of oxygen because the dissolved oxygen acted as collisional quencher. The oxygen distribution was interpreted from images recorded by a CCD camera. These two-dimensional experimental results showed quantitatively how the oxygen concentrations decreased strongly at the narrow plume fringe and that oxygen was depleted at the core of the plume. Separately, dispersivity was measured in a series of nonreactive transport experiments, and biodegradation parameters were evaluated by batch experiments. Two-dimensional numerical simulations with MT3D/RT3D used these parameters, and the predicted oxygen distributions were compared with the experimental results. This measurement method provides a novel approach to investigate details of solute transport and biodegradation in porous media. PMID:12775064

  12. Carbon mineralization and oxygen dynamics in sediments with deep oxygen penetration, Lake Superior

    DEFF Research Database (Denmark)

    Li, Jiying; Crowe, Sean Andrew; Miklesh, David;

    2012-01-01

    To understand carbon and oxygen dynamics in sediments with deep oxygen penetration, we investigated eight locations (160–318-m depth) throughout Lake Superior. Despite the 2–4 weight percent organic carbon content, oxygen penetrated into the sediment by 3.5 to > 12 cm at all locations. Such deep......, suggesting that temporal variability in deeply oxygenated sediments may be greater than previously acknowledged. The oxygen uptake rates (4.4–7.7 mmol m−2 d−1, average 6.1 mmol m−2 d−1) and carbon mineralization efficiency (∼ 90% of deposited carbon) were similar to those in marine hemipelagic and pelagic...... penetration is explained by low sedimentation rates (0.01–0.04 cm yr−1), high solubility of oxygen in freshwater, and a shallow (∼ 2 cm) bioturbation zone. In response mainly to oxygen variations in the bottom waters, the sediment oxygen penetration varied seasonally by as much as several centimeters...

  13. Combination-Combination Hyperchaos Synchronization of Complex Memristor Oscillator System

    OpenAIRE

    Zhang Jin-E

    2014-01-01

    The combination-combination synchronization scheme is based on combination of multidrive systems and combination of multiresponse systems. In this paper, we investigate combination-combination synchronization of hyperchaotic complex memristor oscillator system. Several sufficient conditions are provided to ascertain the combination of two drive hyperchaotic complex memristor oscillator systems to synchronize the combination of two response hyperchaotic complex memristor oscillator systems. Th...

  14. Sensory characteristics changes of red Grenache wines submitted to different oxygen exposures pre and post bottling.

    Science.gov (United States)

    Caillé, Soline; Samson, Alain; Wirth, Jérémie; Diéval, Jean-Baptiste; Vidal, Stéphane; Cheynier, Véronique

    2010-02-15

    It is widely accepted that oxygen contributes to wine development by impacting its colour, aromatic bouquet, and mouth-feel properties. The wine industry can now also take advantage of engineered solutions to deliver known amounts of oxygen into bottles through the closures. This study was aimed at monitoring the influence of oxygen pick-up, before (micro-oxygenation, Mox) and after (nano-oxygenation) bottling, on wine sensory evolution. Red Grenache wines were prepared either by flash release (FR) or traditional soaking (Trad) and with or without Mox during elevage (FR+noMox, FR+Mox, Trad+noMox, Trad+Mox). The rate of nano oxygenation was controlled by combining consistent oxygen transfer rate (OTR) closures and different oxygen controlled storage conditions. Wine sensory characteristics were analyzed by sensory profile, at bottling (T0) and after 5 and 10 months of ageing, by a panel of trained judges. Effects of winemaking techniques and OTR were analyzed by multivariate analysis (principal component analysis and agglomerative hierarchical clustering) and analysis of variance. Results showed that, at bottling, Trad wines were perceived more animal and FR wines more bitter and astringent. Mox wines showed more orange shade. At 5 and 10 months, visual and olfactory differences were observed according to the OTR levels: modalities with higher oxygen ingress were darker and fruitier but also perceived significantly less animal than modalities with lower oxygen. Along the 10 months of ageing, the influence of OTR became more important as shown by increased significance levels of the observed differences. As the mouth-feel properties of the wines were mainly dictated by winemaking techniques, OTR had only little impact on "in mouth" attributes. PMID:20103141

  15. Combined tumor therapy

    International Nuclear Information System (INIS)

    This comprehensive survey of current methods and achievements first takes a look at the two basic therapies, devoting a chapter each to the surgery and radiotherapy of tumors. The principal subjects of the book, however, are the systemic, adjuvant therapy, biological therapies, hyperthermia and various other therapies (as e.g. treatment with ozone, oxygen, or homeopathic means), and psychotherapy. (MG) With 54 figs., 86 tabs

  16. Biochemical requirements for singlet oxygen production by purified human myeloperoxidase.

    OpenAIRE

    Kanofsky, J R; Wright, J; Miles-Richardson, G E; Tauber, A I

    1984-01-01

    The myeloperoxidase (MPO)-hydrogen peroxide (H2O2)-halide systems were found to produce chemiluminescence at 1,268 nm, a characteristic emission band for singlet oxygen (1O2). The emission was enhanced by a factor of 29 +/- 5 in deuterium oxide and was inhibited by the 1O2 quenchers, histidine and azide ion. Inactivation of MPO with heat or with cyanide ion prevented light production. The combined weight of all data strongly supported the production of 1O2 by these enzyme systems. The amount ...

  17. [Hyperbaric oxygen therapy and radiation-induced hemorrhagic cystitis].

    Science.gov (United States)

    Pires, Christophe; Irani, Jacques; Ouaki, Frédéric; Murat, François-Joseph; Doré, Bertrand

    2002-12-01

    Radiotherapy alone or in combination with other modalities is used in the treatment of a large number of pelvic tumours of urological or gynaecological origin. Despite constant progress in this field, medium-term and long-term complications remain frequent and often require difficult long-term management. Radiation cystitis is one of the most frequent complications and directly concerns urologists. Among the various treatment options for haemorrhagic cystitis, hyperbaric oxygen therapy appears to give good short-term and medium-term results. It is currently reserved for cases refractory to the standard treatments for radiation cystitis. PMID:12545623

  18. Radiation hardening of unsaturated polyesters in the presence of oxygen

    International Nuclear Information System (INIS)

    The review is devoted to methods of removing the sticky layer of unhardened resin formed in hardening of polyester lacquer films in air due to co-polymerization inhibition in the surface oxygen layer. Specific features of radiation hardening of oligomers in films, avoiding the inhibition by choosing hardening conditions and composition, combined methods of reducing stickiness are considered. The data available indicate a difference between causes of sticky surface formation in radiation and thermal hardening and methods of avoiding this unwanted effect. Successful solutions of the problem are associated with using monomers active in oxidative polymerization reactions or monomers active in the chain transfer reaction

  19. Improved detection of added water in orange juice by simultaneous determination of the oxygen-18/oxygen-16 isotope ratios of water and ethanol derived from sugars.

    Science.gov (United States)

    Jamin, Eric; Guérin, Régis; Rétif, Mélinda; Lees, Michèle; Martin, Gérard J

    2003-08-27

    A procedure for the analysis of the oxygen-18/oxygen-16 isotope ratio of ethanol derived from the sugars of orange juice using the preparation steps of the SNIF-NMR method followed by pyrolysis-isotope ratio mass spectrometry is presented. The isotopic fractionation induced by the isotope effects of fermentation and distillation have been investigated, and it is shown that reproducible results can be obtained when appropriate analytical conditions are used. It is also shown that the oxygen isotope distribution in the water and organic matter pools of fruits remains quite stable during the harvest period and is not altered by the precipitation rate within the last few days before the fruits are picked. Due to the robustness of the method and the fact that most of the oxygen-18 enrichment from the initial sugars is still present in the end-product, ethanol appears as a convenient internal reference to circumvent the spatial and temporal variability observed for the oxygen-18/oxygen-16 isotope ratio of water. A very strong correlation is observed between the isotopic deviations of ethanol and water, which is altered in the event of a water addition, even at a low level. Combining the information brought by these two parameters leads to a more efficient authenticity testing tool, which avoids false positive cases and provides a lower detection limit for added water in juices not made from concentrate, whatever the origin of the sample tested. PMID:12926859

  20. Some Applications of Fast Neutron Activation Analysis of Oxygen

    International Nuclear Information System (INIS)

    In this thesis we focus on applications of neutron activation of oxygen for several purposes: A) measuring the water level in a laboratory tank, B) measuring the water flow in a pipe system set-up, C) analysing the oxygen in combustion products formed in a modern gasoline SI engine, and D) measuring on-line the amount of oxygen in bulk liquids. A) Water level measurements. The purpose of this work was to perform radiation based water level measurements, aimed at nuclear reactor vessels, on a laboratory scale. A laboratory water tank was irradiated by fast neutrons from a neutron generator. The water was activated at different water levels and the water level was decreased. The produced gamma radiation was measured using two detectors at different heights. The results showed that the method is suitable for measurement of water level and that a relatively small experimental set-up can be used for developing methods for water level measurements in real boiling water reactors based on activated oxygen in the water. B) Water flows in pipe. The goal in this work was to investigate the asymmetric distribution of activity in flow measurements with pulsed neutron activation (PNA) in a laboratory piping system. Earlier investigations had shown a discrepancy between the measured velocity of the activated water by PNA and the true mean velocity in the pipe. This discrepancy decreased with larger distances from the activation point. It was speculated that the induced activity in the pipe did not distribute homogeneously. With inhomogeneous radial distribution of activity in combination with a velocity profile in the pipe, the activated water may not have the same velocity as the mean velocity of water in the pipe. To study this phenomenon, a water-soluble colour was injected into a transparent pipe for simulation of the transport of the activated water. The radial concentration of the colour, at different distances from the activation point, was determined. The result

  1. Some Applications of Fast Neutron Activation Analysis of Oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Owrang, Farshid

    2003-07-01

    In this thesis we focus on applications of neutron activation of oxygen for several purposes: A) measuring the water level in a laboratory tank, B) measuring the water flow in a pipe system set-up, C) analysing the oxygen in combustion products formed in a modern gasoline SI engine, and D) measuring on-line the amount of oxygen in bulk liquids. A) Water level measurements. The purpose of this work was to perform radiation based water level measurements, aimed at nuclear reactor vessels, on a laboratory scale. A laboratory water tank was irradiated by fast neutrons from a neutron generator. The water was activated at different water levels and the water level was decreased. The produced gamma radiation was measured using two detectors at different heights. The results showed that the method is suitable for measurement of water level and that a relatively small experimental set-up can be used for developing methods for water level measurements in real boiling water reactors based on activated oxygen in the water. B) Water flows in pipe. The goal in this work was to investigate the asymmetric distribution of activity in flow measurements with pulsed neutron activation (PNA) in a laboratory piping system. Earlier investigations had shown a discrepancy between the measured velocity of the activated water by PNA and the true mean velocity in the pipe. This discrepancy decreased with larger distances from the activation point. It was speculated that the induced activity in the pipe did not distribute homogeneously. With inhomogeneous radial distribution of activity in combination with a velocity profile in the pipe, the activated water may not have the same velocity as the mean velocity of water in the pipe. To study this phenomenon, a water-soluble colour was injected into a transparent pipe for simulation of the transport of the activated water. The radial concentration of the colour, at different distances from the activation point, was determined. The result

  2. Microbial oceanography of anoxic oxygen minimum zones

    DEFF Research Database (Denmark)

    Ulloa, Osvaldo; Canfield, Donald E; DeLong, Edward F;

    2012-01-01

    Vast expanses of oxygen-deficient and nitrite-rich water define the major oxygen minimum zones (OMZs) of the global ocean. They support diverse microbial communities that influence the nitrogen economy of the oceans, contributing to major losses of fixed nitrogen as dinitrogen (N(2)) and nitrous ...

  3. Oxygen Assessments Ensure Safer Medical Devices

    Science.gov (United States)

    2013-01-01

    A team at White Sands Test Facility developed a test method to evaluate fire hazards in oxygen-enriched environments. Wendell Hull and Associates, located in Las Cruces, New Mexico, entered a Space Act Agreement with NASA and now provides services including fire and explosion investigations, oxygen testing and training, and accident reconstruction and forensic engineering.

  4. In-situ uranium mining with oxygen

    International Nuclear Information System (INIS)

    Gaseous oxygen was dissolved in the leach liquor at concentrations of the order of 300 ppm. This oxygen-containing solution was injected into portions of a field being operated on a commercial basis with hydrogen peroxide as the oxidant. Results indicate that uranium concentrations and production rates were essentially equivalent. 2 refs

  5. Bifunctional electrocatalyst for oxygen/air electrodes

    International Nuclear Information System (INIS)

    Highlights: • Nano-Silver powder was prepared by chemical method. • Ag catalyst was characterized by SEM and XRD studies. • Ag was investigated as bi-functional electrocatalyst for oxygen/air electrodes. • Ag shows good electrochemical activity towards OER and ORR reactions. - Abstract: Nano-Silver powder has been studied as bi-functional electrocatalyst for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline medium. Ag nano-powder has been prepared by a simple wet chemical method with Silver nitrate as precursor and Glucose as reducing agent. X-ray Diffraction and Scanning Electron Microscopy studies were carried out to characterize the Silver catalyst. Electrochemical oxygen evolution characterization shows anodic peak typically at the range between 0.350 and 0.514 V Vs Hg/HgO corresponding to Silver oxidation followed by the onset of oxygen evolution at 0.706 V. Oxygen reduction reaction studies carried out using Rotating Disc Electrode (RDE) confirm the four electron reaction mechanism. Ag catalyst shows promising characteristics for oxygen evolution and oxygen reduction

  6. Oxygen requirement and tolerance of Campylobacter jejuni.

    Science.gov (United States)

    The human pathogen Campylobacter jejuni is considered a microaerophile, yet it has been shown to grow in vitro under atmospheres with elevated oxygen tensions. Hence, a better understanding of the oxygen requirement and tolerance of C. jejuni is required. Bacterial growth was measured under various ...

  7. Efficient oxygen electrocatalysis on special active sites

    DEFF Research Database (Denmark)

    Halck, Niels Bendtsen

    cobalt incorporated in ruthenium dioxide at high overpotentials during the oxygen reduction reaction (ORR). Density functional theory calculations were used to explain this phenomenon. The special active sites concepts are used to propose a general unified approach to increase the efficiency for oxygen...

  8. A rechargeable carbon-oxygen battery

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a rechargeable battery and a method to operate a rechargeable battery having high efficiency and high energy density for storing energy. The battery stores electrical energy in the bonds of carbon and oxygen atoms by converting carbon dioxide into solid carbon and oxygen....

  9. Oxygen requirements of the earliest animals

    DEFF Research Database (Denmark)

    Mills, Daniel Brady; Ward, Lewis M.; Jones, CarriAyne;

    2014-01-01

    A rise in the oxygen content of the atmosphere and oceans is one of the most popular explanations for the relatively late and abrupt appearance of animal life on Earth. In this scenario, Earth's surface environment failed to meet the high oxygen requirements of animals up until the middle to late...

  10. Oxygen partial pressure control for microgravity experiments

    OpenAIRE

    Schulz, Michael; Brillo, Jürgen; Stenzel, Christian; Fritze, Holger

    2012-01-01

    A system consisting of a high-temperature yttrium-stabilized zirconia (YSZ) based oxygen ion pump and potentiometric sensor enables precise measurement and control of oxygen partial pressure, pO2, at elevated temperatures within 0.2 to 10^-20 bar.

  11. Solar Energy Systems for Lunar Oxygen Generation

    Science.gov (United States)

    Colozza, Anthony J.; Heller, Richard S.; Wong, Wayne A.; Hepp, Aloysius F.

    2010-01-01

    An evaluation of several solar concentrator-based systems for producing oxygen from lunar regolith was performed. The systems utilize a solar concentrator mirror to provide thermal energy for the oxygen production process. Thermal energy to power a Stirling heat engine and photovoltaics are compared for the production of electricity. The electricity produced is utilized to operate the equipment needed in the oxygen production process. The initial oxygen production method utilized in the analysis is hydrogen reduction of ilmenite. Utilizing this method of oxygen production a baseline system design was produced. This baseline system had an oxygen production rate of 0.6 kg/hr with a concentrator mirror size of 5 m. Variations were performed on the baseline design to show how changes in the system size and process (rate) affected the oxygen production rate. An evaluation of the power requirements for a carbothermal lunar regolith reduction reactor has also been conducted. The reactor had a total power requirement between 8,320 to 9,961 W when producing 1000 kg/year of oxygen. The solar concentrator used to provide the thermal power (over 82 percent of the total energy requirement) would have a diameter of less than 4 m.

  12. Improved Zirconia Oxygen-Separation Cell

    Science.gov (United States)

    Walsh, John V.; Zwissler, James G.

    1988-01-01

    Cell structure distributes feed gas more evenly for more efficent oxygen production. Multilayer cell structure containing passages, channels, tubes, and pores help distribute pressure evenly over zirconia electrolytic membrane. Resulting more uniform pressure distribution expected to improve efficiency of oxygen production.

  13. Oxygen sensing in iron- and steelmaking

    International Nuclear Information System (INIS)

    The properties of solid oxide electrolytes, the design of oxygen probes, and the benefits of the existing applications of these probes in the various stages of iron and steelmaking are briefly reviewed. Furthermore, the potential future applications of oxygen probes in iron and steelmaking technology are outlined. In this context, the possibilities and limits of long-term measurements in steel melts are discussed

  14. Oxygen isotopic anomaly and solar nebular photochemistry

    International Nuclear Information System (INIS)

    At the cool periphery of the solar nebula, oxygen could photochemically be formed from water. The mixing of 17O and 18O enriched by the self-shielding effect of 16O2 to the dust grain melted by the shock waves there would explain the oxygen isotopic anomaly in the high-temperature mineral of the carbonaceous meteorites. (Auth.)

  15. Aerobic growth at nanomolar oxygen concentrations

    DEFF Research Database (Denmark)

    Stolper, Daniel; Revsbech, Niels Peter; Canfield, Donald Eugene

    2010-01-01

    Escherichia coli K-12, chosen for its well-understood biochemistry, rapid growth rate, and low-oxygen-affinity terminal oxidase, grows at oxygen levels of ≤ 3 nM, two to three orders of magnitude lower than previously observed for aerobes. Our study expands both the environmental range and temporal history of...... aerobic organisms....

  16. Acceleration of oxygen decline in the tropical Pacific over the past decades by aerosol pollutants

    Science.gov (United States)

    Ito, T.; Nenes, A.; Johnson, M. S.; Meskhidze, N.; Deutsch, C.

    2016-06-01

    Dissolved oxygen in the mid-depth tropical Pacific Ocean has declined in the past several decades. The resulting expansion of the oxygen minimum zone has consequences for the region's ecosystem and biogeochemical cycles, but the causes of the oxygen decline are not yet fully understood. Here we combine models of atmospheric chemistry, ocean circulation and biogeochemical cycling to test the hypothesis that atmospheric pollution over the Pacific Ocean contributed to the redistribution of oxygen in deeper waters. We simulate the pollution-induced enhancement of atmospheric soluble iron and fixed nitrogen deposition, as well as its impacts on ocean productivity and biogeochemical cycling for the late twentieth century. The model reproduces the magnitude and large-scale pattern of the observed oxygen changes from the 1970s to the 1990s, and the sensitivity experiments reveal the reinforcing effects of pollution-enhanced iron deposition and natural climate variability. Despite the aerosol deposition being the largest in mid-latitudes, its effect on oceanic oxygen is most pronounced in the tropics, where ocean circulation transports added iron to the tropics, leading to an increased regional productivity, respiration and subsurface oxygen depletion. These results suggest that anthropogenic pollution can interact and amplify climate-driven impacts on ocean biogeochemistry, even in remote ocean biomes.

  17. A highly accurate method for determination of dissolved oxygen: Gravimetric Winkler method

    International Nuclear Information System (INIS)

    Highlights: ► Probably the most accurate method available for dissolved oxygen concentration measurement was developed. ► Careful analysis of uncertainty sources was carried out and the method was optimized for minimizing all uncertainty sources as far as practical. ► This development enables more accurate calibration of dissolved oxygen sensors for routine analysis than has been possible before. - Abstract: A high-accuracy Winkler titration method has been developed for determination of dissolved oxygen concentration. Careful analysis of uncertainty sources relevant to the Winkler method was carried out and the method was optimized for minimizing all uncertainty sources as far as practical. The most important improvements were: gravimetric measurement of all solutions, pre-titration to minimize the effect of iodine volatilization, accurate amperometric end point detection and careful accounting for dissolved oxygen in the reagents. As a result, the developed method is possibly the most accurate method of determination of dissolved oxygen available. Depending on measurement conditions and on the dissolved oxygen concentration the combined standard uncertainties of the method are in the range of 0.012–0.018 mg dm−3 corresponding to the k = 2 expanded uncertainty in the range of 0.023–0.035 mg dm−3 (0.27–0.38%, relative). This development enables more accurate calibration of electrochemical and optical dissolved oxygen sensors for routine analysis than has been possible before.

  18. Numerical analysis of the primary processes controlling oxygen dynamics on the Louisiana Shelf

    Directory of Open Access Journals (Sweden)

    L. Yu

    2014-10-01

    Full Text Available The Louisiana shelf in the northern Gulf of Mexico receives large amounts of freshwater and nutrients from the Mississippi/Atchafalaya River system. These river inputs contribute to widespread bottom-water hypoxia every summer. In this study, we use a physical-biogeochemical model that explicitly simulates oxygen sources and sinks on the Louisiana shelf to identify the key mechanisms controlling hypoxia development. First, we validate the model simulation against observed dissolved oxygen concentrations, primary production, water column respiration, and sediment oxygen consumption. In the model simulation, heterotrophy is prevalent in shelf waters throughout the year except near the mouths of the Mississippi and Atchafalaya Rivers where primary production exceeds respiratory oxygen consumption during June and July. During this time, efflux of oxygen to the atmosphere, driven by photosynthesis and surface warming, becomes a significant oxygen sink while the well-developed pycnocline isolates autotrophic surface waters from the heterotrophic and hypoxic waters below. A substantial fraction of primary production occurs below the pycnocline in summer. We investigate whether this primary production below the pycnocline is mitigating the development of hypoxic conditions with the help of a sensitivity experiment where we disable biological processes in the water column (i.e. primary production and water column respiration. In this experiment below-pycnocline primary production reduces the spatial extent of hypoxic bottom waters only slightly. Our results suggest that the combination of physical processes and sediment oxygen consumption largely determine the spatial extent and dynamics of hypoxia on the Louisiana shelf.

  19. Anaerobe Tolerance to Oxygen and the Potentials of Anaerobic and Aerobic Cocultures for Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    M.T. Kato

    1997-12-01

    Full Text Available The anaerobic treatment processes are considered to be well-established methods for the elimination of easily biodegradable organic matter from wastewaters. Some difficulties concerning certain wastewaters are related to the possible presence of dissolved oxygen. The common belief is that anaerobes are oxygen intolerant. Therefore, the common practice is to use sequencing anaerobic and aerobic steps in separate tanks. Enhanced treatment by polishing off the residual biodegradable oxygen demand from effluents of anaerobic reactors, or the biodegradation of recalcitrant wastewater pollutants, usually requires sequenced anaerobic and aerobic bacteria activities. However, the combined activity of both bacteria can also be obtained in a single reactor. Previous experiments with either pure or mixed cultures showed that anaerobes can tolerate oxygen to a certain extent. The oxygen toxicity to methanogens in anaerobic sludges was quantified in batch experiments, as well as in anaerobic reactors. The results showed that methanogens have a high tolerance to oxygen. In practice, it was confirmed that dissolved oxygen does not constitute any detrimental effect on reactor treatment performance. This means that the coexistence of anaerobic and aerobic bacteria in one single reactor is feasible and increases the potentials of new applications in wastewater treatment

  20. Neuroradiology of extracorporeal membrane oxygenation

    International Nuclear Information System (INIS)

    Extracorporeal membrane oxygenation (ECMO) is a new method of treating respiratory diseases, especially meconium aspiration, in newborns. It requires continued heparinization of the infant and carries the risk of intracranial bleeding. At the author's institution this risk is monitored with daily US examinations. CT is routinely performed at the end of treatment, or at other times to confirm the presence of any pathology that might require the cessation of ECMO treatment. Of the first 62 newborns receiving ECMO therapy, all underwent daily US examinations; 48 underwent CT. In ten patients (16%) hemorrhages developed that were detected on US; the incidence was evenly distributed between primary intraventricular and parenchymal bleeding. Five of these patients died without CT having been performed. Follow-up CT scans in another five also showed hemorrhage. In five patients CT scans showed definite small punctate areas of bleeding in unusual locations, not visible on US. CT scans in another four patients were suspicious for similar bleeding. One subarachnoid hemorrhage was found. In three infants performed widening of the interhemispheric fissure was seen, and six others had probable abnormal widening of the fissure. Overall, 14 (29%) CT scans were definitely abnormal and 21% probably abnormal. Follow-up has not been significantly long enough to allow evaluation the significance of the smaller bleeding areas and interhemispheric fissure widening seen on CT. At this time, both US and CT have a definite role in the care of newborn infants undergoing ECMO

  1. Radio-frequency discharges in oxygen: I. Particle-based modelling

    International Nuclear Information System (INIS)

    In this series of three papers we present results from a combined experimental and theoretical, particle-based study to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte Carlo model on which the theoretical description is based is described in this paper. It treats space charge fields and transport processes on an equal footing with the most important plasma-chemical reactions. For given external voltage and pressure, the model determines the electric potential within the discharge and the distribution functions for electrons, negatively charged atomic oxygen and positively charged molecular oxygen. Previously used scattering and reaction cross section data are critically assessed and in some cases modified. To validate our model, we compare the densities in the bulk of the discharge with experimental data and find good agreement, indicating that essential aspects of an oxygen discharge are captured

  2. The effect of oxygenate molecular structure on soot production in direct-injection diesel engines.

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, Charles K. (Lawrence Livermore National Laboratory, Livermore, CA); Pitz, William J. (Lawrence Livermore National Laboratory, Livermore, CA); Mueller, Charles J.; Martin, Glen M.; Pickett, Lyle M.

    2003-06-01

    A combined experimental and kinetic modeling study of soot formation in diesel engine combustion has been used to study the addition of oxygenated species to diesel fuel to reduce soot emissions. This work indicates that the primary role of oxygen atoms in the fuel mixture is to reduce the levels of carbon atoms available for soot formation by fixing them in the form of CO or COz. When the structure of the oxygenate leads to prompt and direct formation of CO2, the oxygenate is less effective in reducing soot production than in cases when all fuel-bound 0 atoms produce only CO. The kinetic and molecular structure principles leading to this conclusion are described.

  3. Theoretical analysis of ozone generation by pulsed dielectric barrier discharge in oxygen

    Science.gov (United States)

    Wei, L. S.; Zhou, J. H.; Wang, Z. H.; Cen, K. F.

    2007-08-01

    The use of very short high-voltage pulses combined with a dielectric layer results in high-energy electrons that dissociate oxygen molecules into atoms, which are a prerequisite for the subsequent production of ozone by collisions with oxygen molecules and third particles. The production of ozone depends on both the electrical and the physical parameters. For ozone generation by pulsed dielectric barrier discharge in oxygen, a mathematical model, which describes the relation between ozone concentration and these parameters that are of importance in its design, is developed according to dimensional analysis theory. A formula considering the ozone destruction factor is derived for predicting the characteristics of the ozone generation, within the range of the corona inception voltage to the gap breakdown voltage. The trend showing the dependence of the concentration of ozone in oxygen on these parameters generally agrees with the experimental results, thus confirming the validity of the mathematical model.

  4. Oxygen transfer in human carotid artery bifurcation

    Institute of Scientific and Technical Information of China (English)

    Z.G.Zhang; Y.B.Fan; X.Y.Deng

    2007-01-01

    Arterial bifurcations are places where blood flow may be disturbed and slow recirculation flow may occur.To reveal the correlation between local oxygen transfer and atherogenesis, a finite element method was employed to simulate the blood flow and the oxygen transfer in the human carotid artery bifurcation. Under steady-state flow conditions, the numerical simulation demonstrated a variation in local oxygen transfer at the bifurcation, showing that the convective condition in the disturbed flow region may produce uneven local oxygen transfer at the blood/wall interface.The disturbed blood flow with formation of slow eddies in the carotid sinus resulted in a depression in oxygen supply to the arterial wall at the entry of the sinus, which in turn may lead to an atherogenic response of the arterial wall, and contribute to the development of atherosclerotic stenosis there.

  5. Tin release from oxygenated Zircaloy-4

    International Nuclear Information System (INIS)

    Characterized samples of oxygenated Zircaloy were heated in a Knudsen-cell apparatus to 2400 K. The vapour pressure of tin above the Zircaloy was measured as a function of temperature, oxygen content and time. Activity coefficients on the order of 10-2 were measured for tin in Zircaloy for oxygen contents up to 17 atom %. Above that oxygen content, the apparent activity coefficient was 10 times lower; however, this probably arose from diffusion control of the tin volatilization, and not from an enhanced attraction of tin to the Zircaloy lattice at high oxygen contents. The derived tin diffusion coefficient was high, about 3.8 x 10-5 cm2·s-1, probably dominated by diffusion through defects in the lattice and along grain boundaries. (author)

  6. Oxygen diffusion in vanadium-based alloys

    International Nuclear Information System (INIS)

    The experimental study of transport and equilibrium properties of oxygen in vanadium-based alloys was made by EMF measurements on solid electrolytic cells over the temperature range of 873 to 14230K. The oxygen diffusion in vanadium was not significantly modified by small additions of Ti, Cr, Ni, Nb and Ta. The increase in the activation energy for oxygen diffusion in the V-based alloys containing Cr, Ni, Nb and Ta probably reflects the effect of these substitutional solutes on the activity coefficient of oxygen. The oxygen activity was increased by the addition of 1 at % of Cr, Ni and Nb, and decreased by the addition of Ti and Ta. However, the effects in the alloys containing Nb and Ta are very small

  7. Thin film oxygen partial pressure sensor

    Science.gov (United States)

    Wortman, J. J.; Harrison, J. W.; Honbarrier, H. L.; Yen, J.

    1972-01-01

    The development is described of a laboratory model oxygen partial pressure sensor using a sputtered zinc oxide thin film. The film is operated at about 400 C through the use of a miniature silicon bar. Because of the unique resistance versus temperature relation of the silicon bar, control of the operational temperature is achieved by controlling the resistance. A circuit for accomplishing this is described. The response of sputtered zinc oxide films of various thicknesses to oxygen, nitrogen, argon, carbon dioxide, and water vapor caused a change in the film resistance. Over a large range, film conductance varied approximately as the square root of the oxygen partial pressure. The presence of water vapor in the gas stream caused a shift in the film conductance at a given oxygen partial pressure. A theoretical model is presented to explain the characteristic features of the zinc oxide response to oxygen.

  8. Oxygen measurements in thin ribbon silicon

    Science.gov (United States)

    Hyland, S. L.; Ast, D. G.; Baghdadi, A.

    1987-03-01

    The oxygen content of thin silicon ribbons grown by the dendritic web technique was measured using a modification of the ASTM method based on Fourier transform infrared spectroscopy. Web silicon was found to have a high oxygen content, ranging from 13 to 19 ppma, calculated from the absorption peak associated with interstitial oxygen and using the new ASTM conversion coefficient. The oxygen concentration changed by about 10 percent along the growth direction of the ribbon. In some samples, a shoulder was detected on the absorption peak. A similar shoulder in Czochralski grown material has been variously interpreted in the literature as due to a complex of silicon, oxygen, and vacancies, or to a phase of SiO2 developed along dislocations in the material. In the case of web silicon, it is not clear which is the correct interpretation.

  9. Pulmonary ventilation: dynamic MRI with inhalation of molecular oxygen

    International Nuclear Information System (INIS)

    We have recently demonstrated a non-invasive technique to visualize pulmonary ventilation in humans with inhalation of molecular oxygen as a paramagnetic contrast agent. In the current study, T1 shortening of lung tissue by inhalation of oxygen was observed (P2) in a pig, resulting in excellent correlation (r2=0.997). Dynamic wash-in and wash-out MR ventilation images as well as dynamic wash-in wash-out signal intensity versus time curves were obtained. The mean wash-in decay constants were 26.8±10.5 s in the right lung, and 26.3±9.5 s in the left lung. The mean wash-out decay constants were 23.3±11.3 s in the right lung, and 20.8±10.5 s in the left lung. Dynamic assessment of pulmonary ventilation is feasible using oxygen-enhanced MR imaging, which could provide dynamic MR ventilation-perfusion imaging in combination with recently developed MR perfusion imaging technique, and thus a robust tool for the study of pulmonary physiology and pathophysiology

  10. Methane oxidation coupled to oxygenic photosynthesis in anoxic waters.

    Science.gov (United States)

    Milucka, Jana; Kirf, Mathias; Lu, Lu; Krupke, Andreas; Lam, Phyllis; Littmann, Sten; Kuypers, Marcel M M; Schubert, Carsten J

    2015-09-01

    Freshwater lakes represent large methane sources that, in contrast to the Ocean, significantly contribute to non-anthropogenic methane emissions to the atmosphere. Particularly mixed lakes are major methane emitters, while permanently and seasonally stratified lakes with anoxic bottom waters are often characterized by strongly reduced methane emissions. The causes for this reduced methane flux from anoxic lake waters are not fully understood. Here we identified the microorganisms and processes responsible for the near complete consumption of methane in the anoxic waters of a permanently stratified lake, Lago di Cadagno. Interestingly, known anaerobic methanotrophs could not be detected in these waters. Instead, we found abundant gamma-proteobacterial aerobic methane-oxidizing bacteria active in the anoxic waters. In vitro incubations revealed that, among all the tested potential electron acceptors, only the addition of oxygen enhanced the rates of methane oxidation. An equally pronounced stimulation was also observed when the anoxic water samples were incubated in the light. Our combined results from molecular, biogeochemical and single-cell analyses indicate that methane removal at the anoxic chemocline of Lago di Cadagno is due to true aerobic oxidation of methane fuelled by in situ oxygen production by photosynthetic algae. A similar mechanism could be active in seasonally stratified lakes and marine basins such as the Black Sea, where light penetrates to the anoxic chemocline. Given the widespread occurrence of seasonally stratified anoxic lakes, aerobic methane oxidation coupled to oxygenic photosynthesis might have an important but so far neglected role in methane emissions from lakes. PMID:25679533

  11. Structure of Greyhound hemoglobin: origin of high oxygen affinity.

    Science.gov (United States)

    Bhatt, Veer S; Zaldívar-López, Sara; Harris, David R; Couto, C Guillermo; Wang, Peng G; Palmer, Andre F

    2011-05-01

    This study presents the crystal structure of Greyhound hemoglobin (GrHb) determined to 1.9 Å resolution. GrHb was found to crystallize with an α₁β₁ dimer in the asymmetric unit and belongs to the R2 state. Oxygen-affinity measurements combined with the fact that GrHb crystallizes in the R2 state despite the high-salt conditions used for crystallization strongly indicate that GrHb can serve as a model high-oxygen-affinity hemoglobin (Hb) for higher mammals, especially humans. Structural analysis of GrHb and its comparison with the R2-state of human Hb revealed several regions that can potentially contribute to the high oxygen affinity of GrHb and serve to rationalize the additional stability of the R2-state of GrHb. A previously well studied hydrophobic cluster of bar-headed goose Hb near α119 was also incorporated in the comparison between GrHb and human Hb. Finally, a structural comparison with generic dog Hb and maned wolf Hb was conducted, revealing that in contrast to GrHb these structures belong to the R state of Hb and raising the intriguing possibility of an additional allosteric factor co-purifying with GrHb that can modulate its quaternary structure. PMID:21543841

  12. Electrochemical Oxygen Sensor Development for Liquid Sodium

    Science.gov (United States)

    Nollet, Billy K.

    Safe operation of a sodium-cooled fast reactor (SFR) requires in-depth understanding of the corrosion implications of liquid sodium coolant on reactor materials. Dissolved oxygen concentration is of particular importance in characterizing sodium attack, so an accurate means of measuring and controlling oxygen is crucial. There is significant room for improvement in current oxygen sensing technology, so extensive research has been conducted at the University of Wisconsin-Madison to address this issue. Experimental facilities and electrochemical oxygen sensors have been developed, tested, and analyzed. This research is discussed in detail in this report. The oxygen sensors tested in this research were developed using a yttria stabilized zirconia (YSZ) electrolyte whereas many of the past research in this field was conducted with yttria doped thoria (YDT or YST) electrolytes. Thorium, an alpha emitter, is expensive and increasingly difficult to acquire, so motivation to switch to a new material exists. YSZ is commonly used as the electrolyte for solid oxide fuel cells, and ample data is available for high temperature ionic conduction of this material. While some work has been done with YSZ in oxygen sensors (the automotive field, for example, uses YSZ O2 sensors), research on YSZ sensors in sodium is limited. A thorough study of YSZ-based electrochemical oxygen sensors must include detailed corrosion testing and analysis of YSZ in liquid sodium, careful oxygen sensor development and testing, and finally, a comprehensive analysis of the acquired sensor data. The research presented in this report describes the design and development of an electrochemical oxygen sensor for use in sodium using a YSZ electrolyte through the previously-mentioned steps. The designed sensors were subjected to a series of hypotheses which advance common understanding of oxygen sensor signal. These results were used in conjunction with past research to form reliable conclusions.

  13. Enhanced optical oxygen sensing using a newly synthesized ruthenium complex together with oxygen carriers.

    Science.gov (United States)

    Ertekin, Kadriye; Kocak, Suleyman; Sabih Ozer, M; Aycan, Sule; Cetinkaya, Bekir

    2003-11-12

    In this article, an emission based, simple and fast method is proposed for the determination of gaseous oxygen. A newly synthesized fluorophore, dichloro-{2,6-bis[1-(4-dimethylamino-phenylimino) ethyl]pyridine}ruthenium(II) has been used for oxygen sensing together with oxygen carrier perfluorochemicals (PFCs) in silicon matrix. It should be noted that the solubility of oxygen in fluorocarbons is about three to ten times large as that observed in the parent hydrocarbons or in water, respectively. Employed PFCs are chemically and biochemically inert, have high dissolution capacities for oxygen, and, once doped into sensing film, considerably enhance the response of sensing agent. PMID:18969220

  14. Oxygen and animal evolution: Did a rise of atmospheric oxygen trigger the origin of animals?

    DEFF Research Database (Denmark)

    Mills, Daniel Brady; Canfield, Donald Eugene

    2014-01-01

    Recent studies challenge the classical view that the origin of animal life was primarily controlled by atmospheric oxygen levels. For example, some modern sponges, representing early-branching animals, can live under 200 times less oxygen than currently present in the atmosphere - levels commonly...... thought to have been maintained prior to their origination. Furthermore, it is increasingly argued that the earliest animals, which likely lived in low oxygen environments, played an active role in constructing the well-oxygenated conditions typical of the modern oceans. Therefore, while oxygen is still...

  15. Muscular Oxygen Uptake Kinetics in Aged Adults.

    Science.gov (United States)

    Koschate, J; Drescher, U; Baum, K; Eichberg, S; Schiffer, T; Latsch, J; Brixius, K; Hoffmann, U

    2016-06-01

    Pulmonary oxygen uptake (V˙O2) kinetics and heart rate kinetics are influenced by age and fitness. Muscular V˙O2 kinetics can be estimated from heart rate and pulmonary V˙O2. In this study the applicability of a test using pseudo-random binary sequences in combination with a model to estimate muscular V˙O2 kinetics was tested. Muscular V˙O2 kinetics were expected to be faster than pulmonary V˙O2 kinetics, slowed in aged subjects and correlated with maximum V˙O2 and heart rate kinetics. 27 elderly subjects (73±3 years; 81.1±8.2 kg; 175±4.7 cm) participated. Cardiorespiratory kinetics were assessed using the maximum of cross-correlation functions, higher maxima implying faster kinetics. Muscular V˙O2 kinetics were faster than pulmonary V˙O2 kinetics (0.31±0.1 vs. 0.29±0.1 s; p=0.004). Heart rate kinetics were not correlated with muscular or pulmonary V˙O2 kinetics or maximum V˙O2. Muscular V˙O2 kinetics correlated with maximum V˙O2 (r=0.35; p=0.033). This suggests, that muscular V˙O2 kinetics are faster than estimates from pulmonary V˙O2 and related to maximum V˙O2 in aged subjects. In the future this experimental approach may help to characterize alterations in muscular V˙O2 under various conditions independent of motivation and maximal effort. PMID:27116341

  16. Hydrocodone Combination Products

    Science.gov (United States)

    Hydrocodone combination products may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: nausea vomiting ... slowed or irregular breathing chest tightness Hydrocodone combination products may cause other side effects. Call your doctor if you have any ...

  17. Effective Nutritional Supplement Combinations

    Science.gov (United States)

    Cooke, Matt; Cribb, Paul J.

    Few supplement combinations that are marketed to athletes are supported by scientific evidence of their effectiveness. Quite often, under the rigor of scientific investigation, the patented combination fails to provide any greater benefit than a group given the active (generic) ingredient. The focus of this chapter is supplement combinations and dosing strategies that are effective at promoting an acute physiological response that may improve/enhance exercise performance or influence chronic adaptations desired from training. In recent years, there has been a particular focus on two nutritional ergogenic aids—creatine monohydrate and protein/amino acids—in combination with specific nutrients in an effort to augment or add to their already established independent ergogenic effects. These combinations and others are discussed in this chapter.

  18. [Is it necessary to humidify inhaled low-flow oxygen or low-concentration oxygen?].

    Science.gov (United States)

    Miyamoto, Kenji

    2004-02-01

    In Japan, oxygen is routinely humidified in almost every hospital and clinic. In contrast, in Europe and North America, oxygen is not humidified as long as the oxygen flow is less than 4-5 L/min, according to the guidelines for oxygen therapy announced by the ACCP-NHLBI in 1984 and by AARC in 1992. In this paper, we demonstrate mathematically that: 1) the oxygen received through a nasal cannula at 0.5-4 L/min or through a Venturi mask at 24-40% constitutes only a small percentage of the patient's inspiratory tidal volume (2.4-19% and 3.8-24%, respectively), 2) the humidity deficit caused by inhaling unhumidified oxygen through a nasal cannula at 0.5-4 L/min or through a Venturi mask at 24% to 31% is very small compared with the water content delivered from the airway, and 3) this humidity deficit is easily compensated for by increasing the relative humidity of the room air a little, e.g., by only 4% in case of inhalation of 2 L/min of oxygen through a nasal cannula. Similar results are obtained when a Venturi mask is used to inhale oxygen. From these calculations, we conclude that routine humidification of low-flow oxygen or low-concentration oxygen is not justifiable in patients who need oxygen inhalation, as the humidity of room air is sufficient. PMID:15007913

  19. A mechanistic investigation of the oxygen fixation hypothesis and oxygen enhancement ratio

    Science.gov (United States)

    Grimes, David Robert; Partridge, Mike

    2016-01-01

    The presence of oxygen in tumours has substantial impact on treatment outcome; relative to anoxic regions, well-oxygenated cells respond better to radiotherapy by a factor 2.5–3. This increased radio-response is known as the oxygen enhancement ratio. The oxygen effect is most commonly explained by the oxygen fixation hypothesis, which postulates that radical-induced DNA damage can be permanently ‘fixed’ by molecular oxygen, rendering DNA damage irreparable. While this oxygen effect is important in both existing therapy and for future modalities such a radiation dose-painting, the majority of existing mathematical models for oxygen enhancement are empirical rather than based on the underlying physics and radiochemistry. Here we propose a model of oxygen-enhanced damage from physical first principles, investigating factors that might influence the cell kill. This is fitted to a range of experimental oxygen curves from literature and shown to describe them well, yielding a single robust term for oxygen interaction obtained. The model also reveals a small thermal dependency exists but that this is unlikely to be exploitable. PMID:26925254

  20. Oxygen-depleted zones inside reproductive structures of Brassicaceae: implications for oxygen control of seed development

    Science.gov (United States)

    Porterfield, D. M.; Kuang, A.; Smith, P. J.; Crispi, M. L.; Musgrave, M. E.

    1999-01-01

    Growth of Arabidopsis thaliana (L.) Heynh. in decreasing oxygen partial pressures revealed a linear decrease in seed production below 15 kPa, with a complete absence of seed production at 2.5 kPa oxygen. This control of plant reproduction by oxygen had previously been attributed to an oxygen effect on the partitioning between vegetative and reproductive growth. However, plants grown in a series of decreasing oxygen concentrations produced progressively smaller embryos that had stopped developing at progressively younger stages, suggesting instead that their growth is limited by oxygen. Internal oxygen concentrations of buds, pistils, and developing siliques of Brassica rapa L. and siliques of Arabidopsis were measured using a small-diameter glass electrode that was moved into the structures using a micromanipulator. Oxygen partial pressures were found to be lowest in the developing perianth (11.1 kPa) and pistils (15.2 kPa) of the unopened buds. Pollination reduced oxygen concentration inside the pistils by 3 kPa after just 24 h. Inside Brassica silique locules, partial pressures of oxygen averaged 12.2 kPa in darkness, and increased linearly with increasing light levels to 16.2 kPa. Measurements inside Arabidopsis siliques averaged 6.1 kPa in the dark and rose to 12.2 kPa with light. Hypoxia in these microenvironments is postulated to be the point of control of plant reproduction by oxygen.